Fertilization Of Eggs Research Articles

Amino-functionalized mesoporous silica nanoparticles (NH2-MSiNPs) impair the embryonic development of the sea urchin Paracentrotus lividus

Nanoparticles have found use in a wide range of applications, mainly as carriers of active biomolecules. It is thus necessary to assess their toxicity for human health, as well as for the environment, on which there is still a gap of knowledge. In this work, sea urchin Paracentrotus lividus, a widely used model for embryotoxicity and spermiotoxicity, has been used to assess potential detrimental effects of amino-functionalized mesoporous silica nanoparticles (NH2-MSiNPs) on embryonic development. Specifically, gametes quality, embryogenesis morphological and timing alterations, and cellular stress markers, such as mitochondrial functionality, were assessed in presence of different concentrations of NH2-MSiNPs in filtered seawater (FSW). Furthermore, dorsal-ventral axis development and skeletogenesis were characterized by microscopy imaging and gene expression analysis. NH2-MSiNPs determined a strong reduction in the egg fertilization rate. Consequently, the presence of NH2-MSiNPs resulted detrimental in P. lividus embryonic development, with severe morphological alterations correlated with an increased embryos mortality. Finally, NH2-MSiNPs treatment was responsible for other toxic effects, such as reduced mitochondrial function and skeletogenesis alterations, according to the reduced mineralization sites in the endoskeleton formation and the related genes altered expression. Taken together, these results suggest the potential toxic effects of NH2-MSiNPs on the marine ecosystem, with consequences for the development and reproduction of its organisms. Despite their promising potential as carriers of biomolecules, it is pivotal to consider that their uncontrolled use may result harmful to the environment and, consequently, to living organisms.

Efficacy of passive immunization in broiler chicks via an inactivated Escherichia coli autogenous vaccine administered to broiler breeder hens

ABSTRACT Avian pathogenic Escherichia coli (APEC) cause extra-intestinal infections called colibacillosis, which is the dominant bacterial disease in broilers. To date, given the diversity of APEC strains and the need for an acceptable level of protection in day-old chicks, no satisfactory commercial vaccine is available. As part of a French nationwide project, we selected three representative strains among several hundred APEC that cause colibacillosis disease. We first performed experiments to develop colibacillosis in vivo models, using an inoculum of 3 × 107 CFU of each E. coli strain per chick. Two APEC strains (19-381 and 19-383-M1) were found to be highly virulent for day-old chicks, whereas the third strain (19-385-M1) induced no mortality nor morbidity. We then produced an autogenous vaccine using the (Llyod, 1982; MaCQueen, 1967) 19–381 and 19-383-M1 APEC strains and a passive immunization trial was undertaken. Specific-pathogen-free Leghorn hens were vaccinated twice 2 weeks apart, the control group receiving a saline solution. The vaccinated and control hens exhibited no clinical signs, and egg production and fertility of both groups were similar. Fertile eggs were collected for 2 weeks after the second vaccination and chicks were obtained. After challenge with each APEC (19-381 and 19-383-M1), chicks appeared to be partially protected from infection with the 19-383-M1 strain, with 40% mortality compared with 80% for the non-vaccinated chicks. No protection was found when the chicks were challenged with the 19–381 strain. Now, further work is needed to consider some aspects: severity of the pathogen challenge model, persistence of the protection, number of APEC strains in the autogenous vaccine, choice of adjuvants, and heterologous protection by the vaccine made from strain 19-383-M1. RESEARCH HIGHLIGHTS Three APEC strains were characterized and selected to develop in vivo models of colibacillosis. A bivalent autogenous vaccine was produced and a passive immunization trial was carried out. Protection of chicks was demonstrated when challenged with the 19-383-M1 APEC strain (homologous challenge). Further work is needed in particular to evaluate the protection against heterologous challenge.

PCOS Physiopathology and Vitamin D Deficiency: Biological Insights and Perspectives for Treatment.

Recent literature has stressed the importance of vitamin D (VD) in polycystic ovary syndrome (PCOS). Women with PCOS are deficient in VD, particularly those with a higher weight. Hypovitaminosis is a risk factor for glucose intolerance, and reduced levels of VD is associated with insulin resistance and increased diabetes risk. Since women with PCOS and hirsutism seem to have lower levels of VD than women with PCOS without hirsutism, a correlation between VD deficiency and hyperandrogenism may be suggested. Interestingly, VD is crucial for many human physiological functions, including to counteract inflammation and oxidative stress. Some studies evaluated effects of VD supplementation on glucose homeostasis variables, hormonal status, lipid concentrations, and biomarkers of inflammation and oxidative stress among VD-deficient women. Moreover, VD has been shown to play a role in egg quality and fertility. This review aims to show the relationship between VD and the endocrine and metabolic profile of PCOS patients, as well as its implications for their fertility. The supplement of VD to the common therapy can lead to an improvement of the insulin resistance and lipid metabolism, a reduction of circulating androgens, as well as a better response to the induction of ovulation in PCOS women.

Desempenho reprodutivo de perdizes (Rhynchotus rufescens) utilizando diferentes estratégias de acasalamento em cativeiro - relato de caso

ABSTRACT The aim of this study was to evaluate the reproductive performance of red-winged tinamous in captivity using different mating systems during three breeding seasons. The data were collected from August to March during three breeding seasons of the species. Ten couples and four groups of red-winged tinamous were randomly selected for formation of the monogamous and polygynous mating system, respectively, with egg collection from both systems. The traits evaluated were number of eggs per female, egg breaking and egg fertilization. Data were statistically analyzed by the least square method and logistic regression. Animals in couples mating strategy were superior (P<0.05) in terms of number of eggs per female compared to the group mating strategy. High egg breaking rate (P<0.05) in the red-winged tinamous groups was observed. Eggs of animals in couples mating strategy were 5.24 and 11.5 more likely to be fertilized than those of group strategy in two breeding seasons. In general, the reproductive efficiency in terms of low egg breaking, high egg production and fertility was observed for red-winged tinamous from the monogamous mating system.

Environmental DNA dynamics during embryonic development in the rare minnow Gobiocypris rarus

AbstractUnderstanding environmental DNA (eDNA) dynamics in the major developmental stages of fish species is fundamental for developing eDNA methods to aid conservation and management of fish species and/or populations. In this study, we used the model fish species, the rare minnow (Gobiocypris rarus), to assess the temporal changes of its mitochondrial and nuclear eDNA concentrations during its embryonic development in a culture dish experiment. Mitochondrial cytochrome b (Cytb) and nuclear internal transcribed spacer‐1 (ITS1), considered as representative DNA fragments, were amplified by quantitative PCR (qPCR). In this embryo culture trial, spikes in mitochondrial (mt‐) and nuclear (nu‐) eDNA concentrations were found just after egg fertilization and after embryo hatching, and a modest but positive relationship was found between the eDNA concentration and the number of hatched individuals, illustrating eDNA may be used to monitor the spawning and hatching events of externally fertilizing fishes. These findings provided basic information on eDNA dynamics during fish embryonic development and a new insight to design eDNA methods to monitor early developmental stages of fish species.

Effects of dietary 2-(2H-benzotriazol-2-yl)-4-methylphenol (UV-P) exposure on Japanese medaka (Oryzias latipes) in a short-term reproduction assay

Benzotriazole ultraviolet stabilizers (BZT-UVs) are added to various products to prevent damage caused by UV light and have emerged as contaminants of concern. Although BZT-UVs are detected in aquatic biota globally, few studies have assessed their potential toxic effects. The objective of the present study was to assess effects of 2-(2H-Benzotriazol-2-yl)-4-methylphenol (UV-P) on reproductive success of Japanese medaka (Oryzias latipes) in a standard 21-day reproduction assay. Japanese medaka were exposed to dietary UV-P at concentrations of 0, 36, 158, and 634 ng UV-P/g food, for a total of 28 days which included 7 days of exposure prior to the start of the 21-day reproduction assay. No significant effect on egg production or fertilization success was observed. Abundances of transcripts of erα, vtgI, cyp1a, or cyp3a4 were not significantly different in livers from male or female fish exposed to UV-P. However, abundances of transcripts of cyp11a and cyp19a were significantly lower in gonads from female fish. There was a trend of increasing concentrations of E2 and a non-significant increase of T in the 634 ng/g treatment in plasma from female fish exposed to UV-P. Concentrations of 11-KT were unchanged in plasma from males exposed to UV-P. These responses suggest weak perturbation of steroidogenesis, consistent with an antiandrogenic mode of action. However, this perturbation was insufficient to impair reproductive performance. Metabolomics analysis of female livers suggests altered concentrations of various metabolites and biological pathways, including glutathione metabolism, suggesting that UV-P might cause responses related to oxidative stress or phase II metabolism. However, metabolomics revealed no obvious mechanism of toxicity. Overall, results of this study indicate that dietary exposure to UV-P up to 634 ng/g food does not significantly impact reproductive performance of Japanese medaka but impacts on steroidogenesis could indicate a potential mechanism of toxicity which might lead to reproductive impairment in more sensitive species.

P-077 Human sperm acrosome becomes alkalinized during capacitation

Abstract Study question Does during the human sperm capacitation the acrosomal pH (pHa) increases naturally and how it change can be modulate? Summary answer Sperm acrosome is progressively alkalinized during capacitation in a HCO3- and Ca2+ dependent manner. pHa is regulated by V-ATPase and involving the sAC-PKA signaling pathway. What is known already Capacitation involves biochemical and physiological modifications undergone by sperm as they travel through the female reproductive tract. These modifications prepare the sperm to enact the acrosome reaction (AR), an essential step for egg fertilization. Capacitation requires [Ca2+]i and pHi increases. Mouse sperm capacitation is accompanied by acrosomal alkalinization and artificial elevation of the pHa is sufficient to trigger the AR in mouse and human sperm, but it is unknown if the pHa increases physiologically during human sperm capacitation. Study design, size, duration In this work we followed pHa changes during human sperm capacitation (6 h) and evaluated the mechanisms of its regulation using pharmacological tools. Sperm were stained with LysoSensor green and the relative fluorescence measurements for pHa kinetics during capacitation were performed at 15 min of incubation (initial time: 0 h) and after 3 and 6 h of incubation. Independent experiments of at least 3 donors were performed per condition. Participants/materials, setting, methods We used semen samples from 11 healthy donors fulfilled the requirements defined by the OMS (OMS, 2010). Sperm recovered by swim-up were incubated in a capacitating or non-capacitating HTF medium. LysoSensor green fluorescence dye was used to evaluate pHa dynamic during capacitation using single cell epifluorescence microscopy and image-based flow cytometry. Additionally, pHa was evaluated in the presence of specific inhibitors to assess regulatory mechanisms. A linear model was used to study the pHa kinetics. Main results and the role of chance Human sperm pHa is alkalinized progressively at 3 and 6 h of the capacitation (p < 0.05). V-ATPase activity mainly responsible for the acrosome acidity and can modulate at least in part acrosome alkalinization during capacitation (***p<0.001, *p<0.05). V-ATPase is immunolocalized to the acrosome and equatorial segment of human sperm. Bicarbonate (HCO3-) was essential for the pHa increase observed during capacitation and its absence inhibits completely the acrosome alkalinization (**p<0.01, *p<0.05). Inhibition of the Cystic Fibrosis Transmembrane Regulator (CFTR) or the Na+/HCO3- Cotransporter (NBC) partially blocked the pHa changes during capacitation. Extracelular Ca2+ is involved in pHa regulation during capacitation. Under low external Ca2+ the pHa regulation is altered and occurred delay in acrosome alkalinization (*p < 0.05 and **p < 0.001). Finally, we tested a pharmacological blockade of sAC and PKA during capacitation. sAC inhibition did not prevent acrosome alkalinization, but it significantly reduced the rate of the pHa changes as compared to the capacitation control (***p=0.0009), revealing a certain influence. On the other hand, PKA inhibition induced acrosomal acidification at the start of capacitation and accelerated significantly the alkalinization (*p<0.05). Together these results allow us to assume that a signaling pathway mediated to sAC is participating in the pHa regulation. Limitations, reasons for caution Experiments were performed in vitro and due to model limitations is difficult to establish strategies that allow us to know more directly, other molecular mechanisms that regulate the pHa. Wider implications of the findings Our findings show that pHa is subject of regulation during human sperm capacitation. The results provide new insights regarding the molecular mechanisms involved in human sperm capacitation and this knowledge results interesting for the study of specific molecules that inhibit capacitation or AR. Trial registration number Not applicable

AGE DYNAMICS OF REPRODUCTIVE ABILITY AND QUALITY OF AFRICAN CATFISH OFFSPRING UNDER AQUACULTURE CONDITIONS

The work is devoted to study of influence of African catfish age on reproductive ability and viability of its offspring. The problem is relevant, since the issues of age selection of producers have developed relatively recently in industrial aquaculture and have not been enough studied yet. As for practical fish farming, specialists often face the problem of low quality of fish gametes that are too young or old enough. The aim of the study was a comparative assessment of the age-related variability of reproductive ability and viability of African catfish offspring. African catfish breeders at the age of 12, 24, 48, 60 months were selected for the research, four experimental groups were formed. The parameters of fertility and the quality of reproductive products, linear and weight growth of the offspring, as well as its viability were studied. The results of the study showed age-related changes in the quality of reproductive products, embryos developing from them, and subsequent larvae. Differences in egg fertility, viability of embryos and larvae, and the size of larvae obtained from producers of different ages were established. All parameters indicate that the parents’ age significantly affects the quality of their offspring. As for study of reproductive products of female African catfish of different ages by a number of parameters, such as size and diameter of eggs, certain differences were established in morphometric and physiological parameters of eggs and sperm. The study of the effect of parental age on offspring survival rate in embryonic and postembryonic periods showed that the offspring survival rate of first spawning females was the lowest and increased as the parental individuals matured. The viability of offspring in middle-aged groups of breeders was the highest.

Unraveling Metabolite Provisioning to Offspring Through Parental Fluids: A Case Study of the Brazilian Guitarfish, Pseudobatos horkelii.

Elasmobranchs have a very distinct metabolism, and many aspects related to the energetic dynamics of these animals remain poorly investigated. The reproductive period is particularly vulnerable for viviparous species, as part of the energy reserves of the parental biomass is reallocated for gamete production and embryo development. In this context, this study aimed to characterize parental metabolite provisioning to the offspring (both sperm and developing embryos) of the Brazilian Guitarfish, Pseudobatos horkelii, through glucose, β-hydroxybutyrate, triglycerides, and total cholesterol determinations in the uterine liquid (UL) and serum of pregnant females and in the seminal fluid (SF) and serum of males during the copulation period. No significant difference was observed for the analyzed markers between the UL and SF. Except for triglycerides, higher in female serum samples, all other energy markers were present at similar concentrations in the serum of both females and males. When comparing female UL and serum, significant differences were observed for triglycerides and total cholesterol. No differences were observed between SF and serum in males. The results indicate that all markers are being made available to offspring, possibly complementary to the yolk in the case of maternal liquid, and as an additional source for sperm mobilization required during egg fertilization in the case of the paternal fluid. Correlations between the markers in the parental matrices were also noted, compatible with the metabolic pathways activated during energy mobilization in vertebrates. Moreover, distinct marker predominance patterns were also noted for both UL and SF. Energy mobilization characterization directed to offspring through parental fluids aids in unraveling metabolic dynamics during the reproduction stage while also providing support for stress physiology studies to evaluate the indirect effects of parental allostatic overload in both sperm and developing embryos. Finally, energy mobilization assessments of parental fluids may also help elucidate how internal fertilization and viviparity evolved in this very distinct taxonomic group.

Effect of magnetic field on productive and hysiological performance in broiler breeder

The experiment was conducted to determine the effect of magnetic field on the productive and physiological performance of Ross 308. The experimental flock consist of 60 hens and 10 cocks of broiler breeders, which randomly divided into four groups and distributed on the treatments with three replicates for each treatment. The treatments included the control treatment (T1), exposure the stored semen to 803 gauss magnetic field for 24 hours (T2), exposure the fertile eggs to 250 gauss magnetic field for 72 hours before entered the incubator (T3) and exposure the individual cages to 250 gauss magnetic field for 8 weeks (T4), and the performance traits of hen day egg production, egg weight, recorded from magnetization cages group and compared with control group. The results showed a significant decrease (P≤0.05) in fertility and hatchability of total eggs in T2 compared with other groups, and there was no significant difference in the hatchability of fertile eggs and embryonic mortality among treatments, egg weight and the hen day egg production. (HD).

Influence of thermoregulatory (Na & F) genes on performance and blood parameters of F2 and F3 generations of crosses of local and commercial chickens.

High ambient temperatures pose serious productive challenges to poultry farmers in the tropics with adverse consequences such as reduced egg production. A study was undertaken to assess the effect of naked neck (Na) and frizzle (F) genes on the performance of F2 and F3 generations of crosses of commercial and indigenous chickens in Ghana. One thousand, five hundred and sixty-five (1,565) eggs distributed in a randomized complete block design comprising 4 genotypes and 15 hatches were used for the first study. The eggs were produced from 33 each F2 crossbred normal-feathered (nanaff), naked neck (Na), frizzle (F) and both (Na and F) alleles carrying chickens to determine the effects of these genes on fertility and hatchability. Data were analysed using the mixed model procedure of GenStat statistical software. Eggs from birds with the heat-tolerant genes, either in the single or double doses, were significantly more fertile than those from birds without the genes. Eggs of birds carrying the F allele had significantly (P < 0.05) higher hatchability than eggs from birds carrying the Na allele.Subsequently, 199 F3 crossbred chickens obtained from six hatches generated by the F2 generation were used for the evaluation of growth, egg production, haematological and blood biochemical parameters. The genotypic groups were normal feathered (nanaff), homozygous naked neck (NaNaff), heterozygous naked neck (Nanaff), homozygous frizzle (nanaFF), heterozygous frizzle (nanaFf), double homozygous naked neck-frizzle (NaNaFF) and double heterozygous naked neck- frizzle (NanaFf). The Nanaff recorded a significantly (P < 0.05) heavier day-old body weight compared to all other genotypes except the NaNaff birds.The nanaff genotype reached sexual maturity significantly earlier than all other genotypes. Hen day egg production and egg weight were also significantly higher in nanaff birds compared to birds carrying either Na or F allele, or both alleles. All birds carrying the naked neck and frizzle genes had significantly higher packed cell volume (PCV) concentration than the nanaff genotype. The Nanaff genotype recorded a significantly higher blood haemoglobin concentration compared to the nanaff, nanaFf and NaNaFF ones. However, birds carrying the thermoregulatory genes recorded significantly (P < 0.05) higher haemoglobin values except for the heterozygous frizzle. The thermoregulatory genes are of importance in chicken populations in Ghana as they positively influence percentage fertility of chicken eggs and PCV concentrations of chicken blood.

Establishment of Wolbachia infection in Aedes aegypti from Pakistan via embryonic microinjection and semi-field evaluation of general fitness of resultant mosquito population

BackgroundDengue is a mosquito-borne viral disease that is mainly spread by Aedes aegypti. It is prevalent on five continents, predominantly in tropical and sub-tropical zones across the world. Wolbachia bacteria have been extensively used in vector control strategies worldwide. The focus of the current study was to obtain a natural population of Ae. aegypti harbouring Wolbachia and to determine the impact of this bacteria on the new host in a semi-field environment.MethodsWolbachia-infected Aedes albopictus was collected from the city of Lahore, Punjab, Pakistan, and Wolbachia were successfully introduced into laboratory-reared Ae. aegypti via embryonic microinjection. The stable vertical transmission of wAlbB in the host population was observed for eight generations, and the impact of Wolbachia on the general fitness of the host was evaluated in semi-field conditions.ResultsIn the laboratory and semi-field experiments, wAlbB Wolbachia presented a strong cytoplasmic incompatibility (CI) effect, evidenced as zero egg hatching, in crosses between Wolbachia-infected males and wild (uninfected) females of Ae. aegypti. Wolbachia infection had no noticeable impact on the general fitness (P > 0.05), fecundity, body size (females and males) and mating competitiveness of the new host, Ae. aegypti. However, there was a significant decrease in female fertility (egg hatch) (P < 0.001). In addition, under starvation conditions, there was a remarkable decrease (P < 0.0001) in the life span of Wolbachia-infected females compared to uninfected females (4 vs. > 5 days, respectively).ConclusionsWolbachia strain wAlbB has a great potential to control the dengue vector in Ae. aegypti populations by producing 100% CI with a limited burden on its host in natural field conditions. This strain can be used as a biological tool against vector-borne diseases.Graphical

How Egg Storage Duration Prior to Incubation Impairs Egg Quality and Chicken Embryonic Development: Contribution of Imaging Technologies.

Storing fertilised eggs prior to incubation is a frequent practice in commercial hatcheries to coordinate activities and synchronise hatchings. However, the conditions used to store eggs can have major impacts on egg quality and the subsequent viability of chicken embryos. While storage temperatures of 16–18°C are classically used in hatcheries, the duration of storage varies from three to more than 10 days. We explored the effect of storage duration (zero, three or 10 days; D0, D3 and D10, respectively) at 16°C, 80% relative humidity (RH) on egg quality (Broiler, Ross 308), using computed tomography (CT) and classical measurements (egg weight, eggshell strength, egg white pH, Haugh units, yolk index and colour). The results revealed that a storage duration of up to 10 days negatively affected some egg quality traits (yolk index and volume, air chamber volume and egg white pH). Eggs stored for three or 10 days were further incubated for 11, 13 or 15 days (37.8°C, 55% RH). Eggs were analysed by magnetic resonance imaging (MRI) and CT to assess the development of the embryo and internal egg changes occurring during incubation. First, data showed that the fertility and sex ratio of eggs were not affected by storage duration. However, the mortality of viable eggs was increased in the D10 group compared to the D3 group. Results of non-invasive imaging technologies revealed that the storage of eggs for 10 days impaired embryo growth as early as 11 days of incubation (decrease in brain and embryo volumes). Collectively, these data provide new evidence that the duration of egg storage negatively affects embryonic growth. They further corroborate that this parameter is likely to be crucial to synchronising embryonic stages and maybe reducing the hatching window, hence limiting the time spent by newborn chicks in hatchers. In addition, our results highlight that CT and MRI imaging technologies are useful non-invasive tools to evaluate egg quality prior to incubation and the impact of storage (or incubation) practices on developmental growth of the embryo.

Chemerin is secreted by the chicken oviduct, accumulates in egg albumen and could promote embryo development

Understanding of the distribution of chemerin and its receptors, Chemokine-like Receptor 1 (CMKLR1), G Protein-coupled Receptor 1 (GPR1) and Chemokine (C–C motif) receptor-like 2 (CCRL2), in the egg and the embryonic annexes is currently lacking, and their role during embryogenesis remains unknown. By immunoblot using monoclonal anti-chicken antibodies and Enzyme Linked Immunosorbent Assays (ELISA), we found that chemerin is expressed 10 times higher in albumen eggs than in blood plasma, and it is also abundant in the perivitelline membrane but undetectable in yolk. Chicken chemerin can inhibit bacterial growth. By Reverse Transcription—quantitative Polymerisation Chain Reaction (RT-qPCR), western-blot, and immunofluorescence, we show that chemerin is locally produced by the oviduct magnum that participates in albumen formation. Using cultures of magnum explants, we demonstrate that progesterone (P4) and oestradiol (E2) treatment increases chemerin secretion into cultured media and expression in magnum. Chemerin and its three receptors are present in amniotic and Chorio Allantoic Membranes (CAM). Only CMKLR1 expression decreased from embryonic day (ED) 7 to ED11 and remained low until ED18. Chemerin concentrations strongly increased in amniotic fluid at D14 when egg albumen crossed the amniotic membrane. In ovo injections of neutralising chemerin and CMKLR1 antibodies (0.01, 0.1 and 1 µg) increased embryo mortality, which occurred mainly at ED12-13, in a dose-dependent manner. Chemerin treatment increased primary CAM viability. Finally, chemerin and CMKLR1 inhibition within the CAM led to a decrease in blood vessel development and associated angiogenic gene expression. Our results show an important function of the chemerin system during embryo development in chickens, suggesting the potential use of this adipokine as a predictive marker for egg fertility or hatchability.

Evidence That 2n Eggs Explain Partial Hybrids between Medicago sativa and Medicago arborea.

Selected genotypes of alfalfa (Medicago sativa) produce partial hybrids in sexual crosses with Medicago arborea, as reported in Plants (2013). The hybrids contain mostly alfalfa DNA and traits, but also contain DNA and traits from M. arborea. It was proposed in 2008 that the partial hybrids could be explained by fertilization of 2n eggs in alfalfa by normal pollen from M. arborea, followed by partial loss of M. arborea chromosomes during embryogenesis. In this paper, we confirm the presence of 2n eggs in the first alfalfa parents that produced hybrids. The test for 2n eggs involved pollinating 4x alfalfa with pollen from 8x alfalfa. The production of 8x progeny in the cross proved that selected alfalfa parents produced 2n eggs. Thus, 2n eggs appear to explain how the partial hybrids (hereafter hybrids) contain mostly alfalfa DNA and traits. However, two of the six alfalfa plants that did not hybridize with M. arborea also had 2n eggs. Thus, although 2n eggs explain the alfalfa content of hybrids, 2n eggs are not the only factor involved in weakening the hybridization barrier, and in transferring genes to alfalfa from M. arborea.

Practical use of extender and activation solutions for short-term storage of common carp (Cyprinus carpio) milt in a hatchery

The purpose of this study was to investigate the effect of an activation solution (AS) (hatchery water (pH 7.9 and 4 mOsm/kg), Perchec solution (5 mM KCl, 45 mM NaCl, 30 mM Tris-HCl; pH 8.0 and 130 mOsm/kg) and Cheng solution (40 mM NaCl, 20 mM Tris; pH 8.0 and 100 mOsm/kg) on aging sperm of common carp ( Cyprinus carpio ) after storage in a carp artificial seminal plasma (carp ASP: 2 mM CaCl 2 , 1 mM MgSO 4 , 40 mM KCl, 110 mM NaCl, 20 mM Tris; pH 7.5 and 310 mOsm/kg) for 7 days without antibiotics at 4 °C. Fresh milt and undiluted aging milt were used as the control groups. Milt (5 ml) was collected and diluted 1:1 in a carp ASP in 50 ml containers and stored at 4 °C under aerobic conditions. The highest sperm motility was found 45% and 36% at 15 s and 45 s post sperm activation (PSA) in hatchery water. Additionally, the curvilinear velocity (VCL, μm/s) and straight-line velocity (VSL, µm/s) of sperm were the highest in hatchery water and the solution with 5 mM KCl, 45 mM NaCl, 30 mM Tris and pH 8.0, which were above 122 µm/s and 87 µm/s at 15 PSA. Sperm concentration in aging sperm of common carp is known to decrease rapidly, so prior to fertilization, sperm concentration was determined and accurately set to 200,000 sperm per egg. The fertilization of eggs and hatching rate after 7 days of sperm storage in carp ASP were 85–87% and 78–81% in both ASs of hatchery water and Perchec solution. Less than 1% sperm motility, fertilization and hatching rate were observed in undiluted sperm (control). In conclusion, the fertilization ability of aging common carp sperm in carp ASP within different ASs was confirmed for practical use in aquaculture. • Fertilization and hatching rate were 85–87% and 78–81% after 7 days of sperm storage in a carp artificial seminal plasma. • Less than 1% sperm motility, fertilization and hatchery rate were observed in undiluted sperm with a carp artificial seminal plasma. • The fertilization success of old sperm confirmed that the sperm may have good prospect to use in common carp aquaculture.

Technological parameters of brook trout (Salvelinus fontinalis M.) growing at different temperature regimes

The article presents the research results on the growth dynamics of brook trout from caviar to commercial weight at different temperatures. Two groups of brook trout control and experimental individuals were formed to conduct the experiment, kept at different temperature regimes (control – natural water temperature, experimental – with partial heating at other times of the year up to 12 °С). The total duration of the embryonic period for brook trout, starting from fertilization of eggs and ending with free embryos at 2.8 °C was 101 days or 283 degrees-days; at 12 °C, incubation of eggs lasted 30 days (360 degrees-days). The yield of free trout embryos at a constant temperature was 90.5 % of the eggs laid for incubation. The yield of free embryos of brook trout, which was incubated at lower temperatures, was 82.9 %. The complete transition of brook trout larvae at a water temperature of 3.3 °C in the control group to artificial feed took place within 24 days of cultivation. In the experimental group, this transition lasted about ten days. The yield of larvae from embryos in control was 88.2 % in the experiment – 92.0 %. The larvae were then transplanted into 0.5 m3 plastic pools, where they were reared. Planting density in both cases was 5 thousand specimens/m2. The yield from rearing was almost the same and ranged from 91.4 to 92.5 %, but the average weight of young animals reared in heated water was significantly higher and was 3 g against 1.24 g in the control group. The duration of growing one-year-old trout was 240 days. The result was 3234 specimens of one-year-old in control weighing 15.57 g and 3603 specimens in the experiment weighing 35.5 g. The yield from cultivation was 77.0 and 85.8 %, respectively. Fish productivity was 2.5 times higher in the pool where the one-year-old research group was kept. The total weight of fish caught in the experimental group was 77.4 kg. One-year-old brook trout were planted in 30 m3 pools to produce marketable products. The average weight of fish of the control group at planting was 15.6 g, experimental – 35.5 g. 3000 specimens of one-year-old were planted in the pools. The duration of cultivation was 210 days. 2835 specimens were caught from the pools, the control pool, and 2874 specimens from the experimental one, with an average weight of 252.4 and 288.5 g, respectively. The total weight of fish caught was 1.2 times higher in fish of the experimental group. Fish productivity is 3.79 kg/m3 higher.

What an endocrinologist should know about in vitro fertilization treatment and egg storage

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Minimum sperm dose for optimal fertility after artificial insemination in ostriches

Artificial insemination (AI) in ostriches may present potential solutions to high proportions of infertile eggs commonly recorded on commercial farms and assist in reducing the number of males for breeding purposes thereby leading to a more economical and efficient farming system. Although non-invasive methods to collect semen and to artificially inseminate female ostriches have been developed, the insemination dose for maximum fertility of eggs remains unknown. This study was thus conducted to determine the minimum sperm dose that would promote fertility of eggs following AI in female ostriches. A total of 22 South African black ostriches (7 males and 15 females) aged between 2 and 9 years old were used. Semen samples were collected using the dummy female method and diluted 1:4 (semen: diluent) with an ostrich specific semen diluent. Females were inseminated with various sperm doses of diluted semen from the same male three times a week, every second day resulting in a total sperm dose of A: <2.5 × 109, B: 2.5–5 × 109, C: 5–7.5 × 109 and D: 7.5–9.6 × 109 sperm/week. Eggs produced after insemination were opened to determine the fertilization status of the germinal disc (GD) with an unaided eye. The fertile period was then calculated as the number of days fertilized eggs were laid after the last AI. Furthermore, the number of sperm trapped in the outer perivitelline membrane (spermOPVL) above the GD region was counted under fluorescent light, following staining with 4′,6-diamidino-2-phenylindole to determine the rate of sperm loss and the number of days up to when the last egg containing sperm was laid. On average, a mean (±sd) of 35.34 ± 25.72% eggs produced after AI were fertilized. Fertility was lower (mean ± se) when sperm dose A was used (6.71 ± 9.40%), as compared to sperm dose B (46.01 ± 6.71%), C (37.34 ± 6.60%) and D (37.75 ± 8.36%) (P < 0.05). No significant difference was recorded in the latter three doses (P > 0.05). Furthermore, the length of the fertile period and the rate of sperm loss did not differ significantly between sperm doses (P > 0.05). Hence, a sperm dose of between 2.5 and 5 × 109 sperm/week is recommended to optimize fertility after AI in ostriches, as increasing the sperm dose would not benefit fertility. Further studies are, however, needed to determine the frequency of insemination that would maintain fertility throughout the breeding season as well as hatchability of eggs laid after AI.

Review on Production and Reproduction Performance of Indigenous Chicken in Ethiopia

The review summarizes the production and reproductive performance of indigenous chicken in Ethiopia. Even though the total population of indigenous chicken is high enough (98%) than other exotic and crossbreeds, the gain from the poultry sector is still low. Thus, production was encountered under free-range systems with low input for the sector, which limits the profit due to low egg production, small egg size, slow growth rate, late maturity, small clutch size, intensive inclination to broodiness, and high mortality of chickens. The reproductive performance of indigenous chickens includes hatchability and fertility of eggs in addition to the above, which depended on health, nutrition, genetics, storage, incubation condition, and seasonal fluctuation, as well as the number of eggs given to broody hens, was also another factor that causes variability. The hatchability of broody hen reaches up to 85.69%, which was higher than reports from a modern incubator in governmental poultry breed and multiplication centre in Ethiopia (69%) under standard breeding conditions. In terms of the egg and meat production, minimum values were recorded than other exotic and cross breeds because there was no identified productive breed in the country and still in classifications based on ecotypes/location/ and feather plumages of the chicken, even if they have good quality in terms of test for their products. They are also good scavenging as well as foragers and have a high level of disease tolerance, good maternal quality, adapt to harsh conditions and poor-quality feeds. However, there is a lack of knowledge about poultry production, limitation of feed resources, the prevalence of disease as well as institutional and socio-economic conditions are faced