Viable Offspring Research Articles

Restoring fertility and increasing the viability of offspring in sheep by using a feed additive based on "L - asparginate"

Restoring fertility and increasing the viability of offspring in sheep by using a feed additive based on "L - asparginate"

The optimal strategy of incompatible insect technique (IIT) using Wolbachia and the application to malaria control

For decades, techniques to control vector population with low environmental impact have been widely explored in both field and theoretical studies. The incompatible insect technique (IIT) using Wolbachia, based on cytoplasmic incompatibility, is a technique that Wolbachia-infected male mosquitoes are incapable of producing viable offspring after mating with wild-type female mosquitoes. While the IIT method experimentally ensured its effectiveness in several field works, the failure of female mosquito population control by replacement owing to the accidental contamination of Wolbachia-infected female mosquitoes has been a concern and an obstacle in implementing the IIT method in nature. In this study, we develop a population-based IIT mathematical model using cytoplasmic incompatibility and evaluate the effectiveness of the IIT method in scenarios where contamination is present or absent. In addition, by extending the model to assess the disease infection status of the human population with malaria, we evaluate the optimal release strategy and cost for successful disease control. Our study proves that IIT could be a promising method to control mosquito-borne diseases without perfect suppression of vector mosquito population regardless of contamination.

Crossability Relationship between Wild Cotton G. anomalum and G. aridum with Upland Cotton (G. hirsutum)

Background: Utilizing two wild cotton species, Gossypium anomalum [Wawra and Peyritsch (2n=2x=26) B1] and Gossypium aridum [Skovsted (2n=2x=26) D4], extensive wide hybridization event carried out with upland cotton to assess the feasibility and ease of delivering genetic variation responsible for resistance to various stresses. Methods: The crossing was carried out using the wild species and the cultivate varieties of upland cotton in 2021-2022 at TNAU, Coimbatore. Total of 12 crosses were attempted and the various aspect regarding the feasibility success of different crosses was studied. Result: In contrast to their reciprocals, viable offspring were generated in the direct crosses with tetraploid parents employed as seed parents with both wild species. A huge bulk of bolls dropped during the first seven days of pollination and no matured boll set was observed in reciprocals. Most G. anomalum hybrids produce F1 offspring with thick and long leaf hairs which help the plant attain resistance against sucking pests. Through successive backcrosses or chromosome duplication, such genetic material potentially can be utilized furthermore in plant breeding to provide new beneficial resistance traits apart from other significant and relevant features.

MP30-18 EFFECT OF LENGTH OF TIME POST-MORTEM ON QUALITY AND FREEZING CAPACITY OF HUMAN TESTICULAR SPERMATOZOA

You have accessJournal of UrologyCME1 Apr 2023MP30-18 EFFECT OF LENGTH OF TIME POST-MORTEM ON QUALITY AND FREEZING CAPACITY OF HUMAN TESTICULAR SPERMATOZOA Joshua Bitran, Jamie Thomas, Joginder Bidhan, and Ranjith Ramasamy Joshua BitranJoshua Bitran More articles by this author , Jamie ThomasJamie Thomas More articles by this author , Joginder BidhanJoginder Bidhan More articles by this author , and Ranjith RamasamyRanjith Ramasamy More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003258.18AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Post-mortem sperm retrieval (PMSR) has been demonstrated to produce viable offspring, however, there is scarce evidence about how long after death sperm remains viable. PMSR raises several ethical dilemmas including consent, justifiability, and sperm donation, and consequently, laws surrounding PMSR vary widely by country. Some countries ban the procedure in its entirety, while Israel has an opt-in for PMSR when enlisting in the military in Israel. Even within the US, laws vary by state. We hypothesize that sperm viability is more robust than previously reported in the literature. The objective of this study is to report sperm motility and viability based on extraction time post-mortem. METHODS: Patient lists from the Miami-Dade County Medical Examiner Department were analyzed daily in search of a patient who fit criteria of being a male between the ages of 15-60 with sudden death, no hospitalization and without comorbidities. Once a patient was identified, informed consent was obtained from their next of kin. The patient’s testicle was removed and biopsied, and four samples were collected and placed into separate vials containing sperm wash. After initial biopsy, the testicle was stored in a 45F refrigerator. Semen analysis was conducted to determine the viability of the spermatozoa. Biopsies and semen analyses were continued daily until the spermatozoa were no longer viable. Last surgically extracted samples contained minced epididymis and vas deferens, and the testicular collected fluid were cryopreserved using the fast-freezing technique with the aid of a cryoprotector media. Post-thaw was done at 24 hours time point on the postmortem samples. RESULTS: The patient’s testicles were biopsied and analysis was conducted at 13, 34, 58, 82, and 106 hours postmortem. The average spermatozoa viability at each interval was 67%, 57%, 47%, 34% and 22% respectively. Motility with pentoxifylline were also reported at those times: 26%, 19%, 7%, 11%, and 5%. Post-thaw viability and motility at 106 hours postmortem were 5% and 1% respectively. CONCLUSIONS: Our study demonstrated that there are motile and viable sperm from human testes even 100 hours post mortem. This is the first study to demonstrate viable or motile sperm after such a long time after death. These findings will have implications on duration after death at which post-mortem sperm retrieval future can be performed successfully. Source of Funding: NIH Grant R01 DK130991 and Clinician Scientist Development Grant from the ACS to Dr. Ranjith Ramasamy © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e398 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Joshua Bitran More articles by this author Jamie Thomas More articles by this author Joginder Bidhan More articles by this author Ranjith Ramasamy More articles by this author Expand All Advertisement PDF downloadLoading ...

High Divergence of Cuticular Hydrocarbons and Hybridization Success in Two Allopatric Seven-Spot Ladybugs.

The seven-spotted ladybug is a widespread species in the Palearctic, and also acclimated in the Nearctic. It has been classified into different species on the basis of certain morphological characteristics, the geographical origin, and the genitalia structure of both sexes. The morphotypes of North Africa and the Canary Islands are separated, under the name of Coccinella algerica Kovář, 1977, from the rest of the Palearctic and Nearctic populations of Coccinella septempunctata Linnaeus, 1758. In this study, we investigated, on one hand, whether potential reproductive barriers have been established during evolution between the geographically isolated North African and the European seven-spotted ladybugs by performing reciprocal crosses. On the other hand, we assessed their cuticular hydrocarbon (CHC) divergence by GC-MS. The 33 CHCs indentified are with a skeleton of 23 to 32 carbon atoms. These CHCs are linear alkanes (24.9 ± 3.6%) and methyl-branched alkanes (75.1 ± 3.6%) including monomethylalkanes (48.8 ± 2.4%), dimethylalkanes (24.6 ± 4.0%) and trimethylalkanes (2.0 ± 1.0%). Although all the CHC compounds identified are present in the two seven-spotted ladybugs and their F1 and F2 hybrids, their profiles diverged significantly. However, these chemical divergences have not altered the sexual communication to cause reproductive isolation. The two ladybugs interbreed and leave viable and fertile offspring, with even a heterosis effect on reproductive performances, without phenotypic degradation after the F1 generation. So, these chemical differences are just an intraspecific variability in response to heterogeneous environments. The two types of ladybugs can be considered as two different races of the same species with reduced genetic divergence.

Maternal control of triploid seed development by the TRANSPARENT TESTA 8 (TT8) transcription factor in Arabidopsis thaliana

The balance between parental genome dosage is critical to offspring development in both animals and plants. In some angiosperm species, despite the imbalance between maternally and paternally inherited chromosome sets, crosses between parental lines of different ploidy may result in viable offspring. However, many plant species, like Arabidopsis thaliana, present a post-zygotic reproductive barrier, known as triploid block which results in the inability of crosses between individuals of different ploidy to generate viable seeds but also, in defective development of the seed. Several paternal regulators have been proposed as active players in establishing the triploid block. Maternal regulators known to be involved in this process are some flavonoid biosynthetic (FB) genes, expressed in the innermost layer of the seed coat. Here we explore the role of selected flavonoid pathway genes in triploid block, including TRANSPARENT TESTA 4 (TT4), TRANSPARENT TESTA 7 (TT7), SEEDSTICK (STK), TRANSPARENT TESTA 16 (TT16), TT8 and TRANSPARENT TESTA 13 (TT13). This approach allowed us to detect that TT8, a bHLH transcription factor, member of this FB pathway is required for the paternal genome dosage, as loss of function tt8, leads to complete rescue of the triploid block to seed development.

Harnessing Wolbachia cytoplasmic incompatibility alleles for confined gene drive: A modeling study.

Wolbachia are maternally-inherited bacteria, which can spread rapidly in populations by manipulating reproduction. cifA and cifB are genes found in Wolbachia phage that are responsible for cytoplasmic incompatibility, the most common type of Wolbachia reproductive interference. In this phenomenon, no viable offspring are produced when a male with both cifA and cifB (or just cifB in some systems) mates with a female lacking cifA. Utilizing this feature, we propose new types of toxin-antidote gene drives that can be constructed with only these two genes in an insect genome, instead of the whole Wolbachia bacteria. By using both mathematical and simulation models, we found that a drive containing cifA and cifB together creates a confined drive with a moderate to high introduction threshold. When introduced separately, they act as a self-limiting drive. We observed that the performance of these drives is substantially influenced by various ecological parameters and drive characteristics. Extending our models to continuous space, we found that the drive individual release distribution has a critical impact on drive persistence. Our results suggest that these new types of drives based on Wolbachia transgenes are safe and flexible candidates for genetic modification of populations.

The effect of phenotypic heterogeneity on behaviours linked to invasive success

AbstractWhile most introduced species fail to become invasive, those that succeed are a major threat to global biodiversity. To improve the management of invasive species, a predictive understanding of invasion risk is needed. There is strong evidence that invasive success is linked to specific traits of the introduced species, and it is well recognised that phenotypic trait heterogeneity is linked to population viability. However, the effects of population‐level traits, and the contribution of trait heterogeneity to invasive success, remain poorly addressed in invasion biology. Here, we address this gap by quantifying the contribution of founding population phenotypic heterogeneity to reproductive success (a proxy for invasion success). Namely, we use the Trinidadian guppy (Poecilia reticulata) to test the prediction that founding populations composed of phenotypically heterogeneous males produce larger broods of more viable offspring than founding populations of reduced male heterogeneity. We found that founding populations of greater male phenotypic heterogeneity produced larger broods. Furthermore, whilst male sexual behaviour was an important predictor of brood size for all groups of reduced male heterogeneity, this was not observed for phenotypically heterogeneous populations. Taken together, our results provide strong support for the key role phenotypic heterogeneity plays in the invasion process.

Somatic Cell Nuclear Transfer Using Freeze-Dried Protaminized Donor Nuclei.

Somatic cell nuclear transfer (SCNT) is the only nuclear reprogramming method that allows rewinding an adult nucleus into a totipotent state. As such, it offers excellent opportunities for the multiplication of elite genotypes or endangered animals, whose number have shrunk to below the threshold of safe existence. Disappointingly, SCNT efficiency is still low. Hence, it would be wise to store somatic cells from threatened animals in biobanks. We were the first to show that freeze-dried cells allow generating blastocysts upon SCNT. Only a few papers have been published on the topic since then, and viable offspring have not been produced. On the other hand, lyophilization of mammalian spermatozoa has made considerable progress, partially due to the physical stability that protamines provide to the genome. In our previous work, we have demonstrated that a somatic cell could be made more amenable to the oocyte reprogramming by the exogenous expression of human Protamine 1. Given that the protamine also provides natural protection against dehydration stress, we have combined the cell protaminization and lyophilization protocols. This chapter comprehensively describes the protocol for somatic cell protaminization, lyophilization, and its application in SCNT. We are confident that our protocol will be relevant for establishing somatic cells stocks amenable to reprogramming at low cost.

Variaiton in the composition of small molecule compounds in the egg yolks of Asian Short-toed Larks between early and late broods

The egg yolks of birds contain most of the maternally derived materials required for embryo development and are an important factor influencing embryo development and offspring viability. Individual variation in egg-laying date frequently occurs in passerines inhabiting highly seasonal environments. Females laying in early and late stages of the breeding season encounter different environment temperatures and food conditions, which can affect the levels of metabolities in their bodies, thereby altering the transmission of these materials to the eggs. We test a hypothesis that yolk small molecule compounds of Asian Short-toed Lark (Alaudala cheleensis) could vary between early (mid-May) and late (mid-June) broods. Using the UHPLC-MS/MS method, 683 compounds belonging to 21 compound groups are detected in the yolks. The contents of 18 compounds are significantly different between early and late broods. Ten differential compounds are significantly higher in the early laid eggs, among which γ-aminobutyric acid, creatine, prostaglandins, palmitoleic acid, linoleic acid, and trans linoleic acid are related to low environment temperature response. The eggs laid in late stage exhibit significantly higher levels of 5-L-glutamyl-L-alanine and γ-glutamate-leucine, 1,3-dimethyluric acid and mannose, which may be attributed to females in the late group consuming more insects. We suggest conducting a comprehensive investigation to reveal the yolk small molecule compounds mediated maternal effects on offspring phenotypes under varying ecological conditions.

Sympatric Association in Species and Breeds of Pigeons

For understanding the ancestral behavior of pigeons and doves, this composition has an impact. Rock-pigeons with other pigeons are commonly observed in any railway station and ruined building. Due to genetic relations, wild rock-pigeon mix with local or indigenous pigeon, feral pigeon, and tumbler pigeon. They make pairs and produce viable offspring. Pigeon keepers of Bangladesh make pairs between local/rock-pigeon and fancy pigeons and get good fosters always.

English

Ninety backyard gardens in the south-eastern Ethiopian highlands with enset (Ensete ventricosum (Welw.) Cheesman), banana and various annual crops were assessed for the presence of enset root mealybugs (Paraputo ensete (Williams & Matile-Ferrero)). This study presents the first observation of enset root mealybugs on banana. This pest has until now been exclusively recorded on enset in Ethiopia. In the Dilla Zuria district of the Gedeo zone, southern Ethiopia, infested banana mats of the ‘Pisang Awak’ (ABB genome) landrace were observed adjacent to infested enset plants in three small-holder backyard gardens. As roots of banana mats and enset plants were overlapping and intertwined, and large numbers of mealybugs were observed on enset roots, possibly representing an overpopulation, the observed mealybugs on banana might have represented a “chance infestation". The smaller size of mealybugs on banana roots might indicate a non-optimal host status of this crop. Experimental choice and no-choice pot trials however provided another indication of the possible host potential of ‘Pisang Awak’ and of an additional banana cultivar ‘Matooke’ (AAA-East African Highland). The enset root mealybug was able to fully develop, produce viable offspring and survive on both banana cultivars. Not all investigated banana cultivars presented this host status, and the susceptibility of most Musa cultivars remains low. Key words: Choice trials, corm, crawlers, enset suckers, field survey, Musa cultivars, no-choice trials, roots, screenhouse pot trials.

Подготовка производителей судака (Sander lucioperca Linnaeus, 1758) к нересту, нерест и инкубация икры в условиях экспериментальной нерестовой установки

The article presents the materials on the current state of aquaculture in Russia and in the world, in particular, the biotechnology of breeding and rearing pike-perch in recirculating aquaculture systems. Pike perch (Sander lu-cioperca Linnaeus, 1758) is in high demand among the population. There are shown the results of artificial production of pike-perch offsprings in the experimental spawning units, which make it possible to create the conditions for spawning close to those in the open water bodies. The work included 3 stages: holding pike-perch breeders and preparing them for spawning; spawning; incubation of eggs and prelarvae hatching. Methods for stimulating and spawning pike-perch breeders, as well as a method of eggs incubation in industrial conditions are described. It was demonstrated that all males matured in 24 hours after injection, females ‒ in 28 hours. Incubation of fertilized pike-perch eggs was carried out in the nests of the spawning device. Fertilization of eggs at the stage of gastrulation made 70%. As a result of research work, there have been selected the optimal hydrochemical parameters and fish-breeding and biological characteristics of farming pike-perch spawners, of intensive incubation of eggs under the controlled conditions of a spawning unit. In addition, there have been registered the infectious, parasitic and alimentary diseases, the alternative ways of cure and preventive treatment have been presented. The results of studying the production of pike-perch offsprings in the experimental spawning unit prove the possibility of its using on the industrial scale. The development of a method for reproducing pike-perch in industrial conditions using a special spawning unit will allow obtaining the viable offspring in the controlled environmental conditions.

Maternal spawning experience and thermal effects on offspring viability of chub mackerel and their influence on reproductive success

Maternal effects on offspring viability significantly contribute to the productivity and resilience of exploited marine fish populations. The temporal trend of biomass of chub mackerel (Scomber japonicus) in the western North Pacific showed cyclic fluctuation patterns, but it has been rapidly increasing since 2011. Although there are several assumptions regarding the mechanisms of the population dynamics of this species in these waters, there is a contradiction in the effects of thermal environmental conditions on recruitment success. We explored the effects of maternal age and/or previous spawning experience on egg and offspring traits of captive chub mackerel in response to thermal conditions. Moreover, from the relationship between the growth rate and temperature experienced by captive fish, the experienced temperatures of wild specimens were assessed. The sizes of eggs spawned from females aged 1–3 years were negatively correlated with temperature, but the effects of maternal age on egg size and nutrition were significant with larger and nutrient-rich eggs spawned from 2- or 3-year-old females (repeat spawners) than those from 1-year-old females (first-time spawners) at a given temperature. Such temperature- and maternal-age-dependent egg traits reflected the standard length of first-feeding larvae. The effects of maternal age on the starvation tolerance of larvae after hatching and body sizes of first-feeding larvae were also evident in larvae derived from 3-year-old females showing longer starvation tolerance and larger body heights than those from 1-year-old females. Further, larvae derived from 3-year-old females grew significantly faster than those from 1-year-old females at the tested temperatures. The process of ontogenetic development and growth rate of captive specimens until age 25 days were positively correlated with temperature. Meanwhile, the estimated temperatures experienced by wild specimens until age 25 days ranged from 18.0 to 20.3°C. These findings suggested that there were opposing thermal responses between maternal and offspring traits of chub mackerel, but the temperatures experienced by the main recruit fish may be restricted within the range of temperatures available for spawning. We discuss the mechanisms of reproductive success of this species in accordance with the maternal spawning experience and thermal effects on life history traits.

Sperm Cryopreservation as a Tool for Amphibian Conservation: Production of F2 Generation Offspring from Cryo-Produced F1 Progeny

Sperm cryopreservation and biobanking are emerging as tools for supporting genetic management of small and threatened populations in amphibian conservation programs. However, there is little to no evidence demonstrating reproductive maturity and viability of offspring generated with cryopreserved sperm, potentially limiting widespread integration of these technologies. The purpose of this report is to demonstrate that amphibian sperm can be cryopreserved and thawed to successfully produce individuals of an F1 generation that can reach adulthood and reproductive maturity, to generating viable gametes and an F2 generation. Species-specific exogenous hormones were administered to both F0 and F1 adults to stimulate spermiation and oviposition in the eastern tiger salamander (Ambystoma tigrinum), dusky gopher frog (Lithobates sevosa), and Puerto Rican crested toad (Peltophryne lemur). Sperm cells collected non-lethally from F0 adults were cryopreserved, thawed, and used for in vitro fertilization (IVF) to produce F1 offspring. Individuals of the F1 generation are shown to reach adulthood, express viable gametes, and produce offspring through facilitated breeding, or IVF. The production of amphibian F2 generations shown here demonstrates that amphibian sperm collected non-lethally can be banked and used to generate reproductively viable animals of subsequent generations, thus maintaining valuable genetic linages and diversity in threatened amphibian species. The incredible value that cryopreservation of sperm has for long-term genetic management aids in the sustainability of both in situ and ex situ conservation efforts for this taxon.

Drosophila melanogaster females prioritise dietary sterols for producing viable eggs

Limiting calories or specific nutrients without malnutrition, otherwise known as dietary restriction (DR), has been shown to extend lifespan and reduce reproduction across a broad range of taxa. Our recent findings in Drosophila melanogaster show that supplementing flies on macronutrient-rich diets with additional cholesterol can extend lifespan to the same extent as DR, while also sustaining high egg production. Thus, DR may be beneficial for lifespan because it reduces egg production which in turn reduces the mother’s demand for sterols, thus supporting longer lifespan. It is also possible that mothers live longer and lay more eggs on high sterol diets because the diet triggers enhanced somatic maintenance and promotes egg production, but at the cost of diminished egg quality. To test this, we measured the viability of eggs and development of offspring from mothers fed either cholesterol-sufficient or cholesterol-limiting diets. We found that even when the mother’s diet was completely devoid of cholesterol, viable egg production persisted for ∼10 days. Furthermore, we show that sterol-supplemented flies with long lives lay eggs that have high viability and the same developmental potential as those laid by shorter lived mothers on sterol limiting diets. These findings suggest that offspring viability is not a hidden cost of lifespan extension seen in response to dietary sterol supplementation.

Estrogen receptor 1 appears essential for fetal viability in a murine model of premature birth.

Protective effects for adult neurological disorders have been attributed to sex hormones. Using a murine model of prematurity, we evaluated the role of estrogen signaling in the process of perinatal brain injury following exposure to intrauterine inflammation. Intrauterine lipopolysaccharide (LPS) was used to invoke preterm labor and fetal neuroinflammation. Fetal brains were analyzed for changes in Esr1, Esr2 and Cyp19. Dams heterozygous for the Esr1 knockout allele were also given intrauterine LPS to compare delivery and offspring viability to wild type controls. The upregulation in inflammatory cytokines was accompanied by an increase in Esr1 and Esr2 transcripts, though protein levels declined. Cyp19 did not differ by mRNA or protein abundance. Offspring from Esr1 mutants were larger, had a longer gestation and significantly greater mortality. Estrogen signaling is altered in the fetal brains of preterm offspring exposed to neuroinflammatory injury. The reduction of Esr1 and Esr2 proteins with LPS suggests that these proteins are degraded. It is possible that transcriptional upregulation of Esr1 and Esr2 occurs to compensate for the loss of these proteins. Alternatively, the translation of Esr1 and Esr2 mRNAs may be disrupted with LPS while a feedback mechanism upregulates transcription. Intact Esr1 signaling is also associated with early preterm delivery following exposure to intrauterine LPS. A loss of one Esr1 allele delays this process, but appears to do so at the cost of fetal viability. These results suggest estrogen signaling plays opposing roles between maternal and fetal responses to preterm birth.

Parasitism shapes selection by drastically reducing host fitness and increasing host fitness variation.

Determining the effects of parasites on host reproduction is key to understanding how parasites affect the underpinnings of selection on hosts. Although infection is expected to be costly, reducing mean fitness, infection could also increase variation in fitness costs among hosts, both of which determine the potential for selection on hosts. To test these ideas, we used a phylogenetically informed meta-analysis of 118 studies to examine how changes in the mean and variance in the outcome of reproduction differed between parasitized and non-parasitized hosts. We found that parasites had severe negative effects on mean fitness, with parasitized hosts suffering reductions in fecundity, viability and mating success. Parasite infection also increased variance in reproduction, particularly fecundity and offspring viability. Surprisingly, parasites had similar effects on viability when either the male or female was parasitized. These results not only provide the first synthetic, comparative, and quantitative summary of the strong deleterious effects of parasites on host reproductive fitness, but also reveal a consistent role for parasites in shaping the opportunity for selection.

NON-SPECIFIC HETEROSIS ON A COMPLEX OF FEATURES OF ADAPTABILITY ON THE EXAMPLE OF MINI-PIGS

The authors studied the genetic diversity of the reproductive nucleus of mini-pigs at the Institute of Cytology and Genetics (IC&G) of the Siberian Branch of the Russian Academy of Sciences (SB RAS). To do this, the authors used the indicators of individual homo- and heterozygosity, calculated based on the «blood fractions» of large and small forms of domestic pigs, initial for the breeding group. The study showed that the average value of individual heterozygosity (conditionally actual) is 0.800±0.004, while homozygosity for the contribution of large and small forms of the domestic pig is 0.020±0.002 and 0.180±0.010, respectively. The indicator «blood fraction» can have two interpretations: 1) the probability of transmission of the ancestral allele in several generations; 2) the proportion of the genome of the ancestor that is present in the descendant. The authors determined their frequencies, which turned out to be 0.424 and 0.576 as if assuming the presence of a hypothetical locus with different alleles in the large and small forms of the domestic pig (respectively Ak and Am). The authors calculated heterozygosity for the breeding nucleus based on these frequencies while respecting the Hardy-Weinberg law. As a result, it turned out that the unbiased value is 0.493±0.067, which is significantly (P<0.001) less than the observed conditional-actual value. Selection is carried out according to a set of signs of general fitness (state of health, reproductive qualities, the viability of offspring, etc.) during the formation of the reproductive core of the breeding group of mini-pigs of the IC&G SB RAS. Therefore, the authors concluded that the increased heterozygosity of the breeding stock is due to the preferential selection of heterozygotes. But since selection is carried out according to a set of signs of general fitness, it can be stated that in the reproductive core of the selection group there is an effect of nonspecific heterosis due to heterozygosity. As a result, selection into the reproductive nucleus of individuals with high values of individual heterozygosity calculated by the proposed method can provide heterosis based on general adaptiveness.

Mitochondrial networks of cumulus cells and oocyte quality

BACKGROUND: Mitochondria play vital roles in oocyte functions and they are critical indicators of oocyte quality which is important for fertilization and development into viable offspring. Quality-compromised oocytes in which mitochondrial dysfunction plays a significant role are correlated with infertility, developmental disorders and embryo loss. A significant role in the oocytes of cytoplasmic accumulation and a sufficient amount of the mitochondrial pool of oocytes is played by the cumulus cells surrounding it.
 AIM: to conduct a comparative analysis between the state of mitochondrial networks of cumulus cells and the quality of oocytes.
 MATERIALS AND METHODS: The study included 22 women aged 28 to 37 years inclusive (mean age 32.3 1.2 years) with tubal infertility. During the assisted reproductive technology procedures, 74 oocytes were obtained. 39 good quality oocytes and their cumulus cells were compared with 35 bad quality oocytes and their cumulus cells respectively. After puncture of ovarian follicles cumulus cells were isolated and stained with fluorescent dye for cell tracing and mitochondrial imaging in vivo. The method of confocal microscopy was used to analyze the three-dimensional organization of mitochondria in 2030 cells of one pool of follicular fluid. The following parameters were used to evaluate the mitochondrial network: fluorescence decay time and fluorescence intensity.
 RESULTS: The decay time of fluorescence in cumulus cells associated with a good quality oocyte was significantly higher (p = 0.032) than in the case of identification of oocytes with negative signs.
 CONCLUSION: The structure of mitochondrial networks in cumulus cells correlates (r = 0.76) with the quality of oocytes.