Study Of Reproductive Biology Research Articles

Effects of Pollen Germination and Pollen Tube Growth under Different Temperature Stresses in Mango (Mangifera indica L.) by Metabolome.

The dramatic temperature fluctuations spurred by global warming and the accompanying extreme weather events inhibit mango growth and threaten mango productivity. Particularly, mango flowering is highly sensitive to temperature changes. The mango fruit setting rate was significantly positively correlated with pollen activity, and pollen activity was regulated by different metabolites. In this study, the in vitro pollen of two mango varieties ('Renong No.1' and 'Jinhuang'), in which sensitivity to temperature differed significantly, were subjected to different temperature stresses (15 °C, 25 °C and 35 °C), and their metabolomics were analyzed. The present results showed that 775 differential metabolites were screened by liquid chromatography-mass spectrometry and divided into 12 categories. The two varieties had significant differences in metabolite expression under different temperature stresses and the effect of low temperature on 'Renong No.1' mainly focused on amino acid metabolism, while the effect on 'Jinhuang' was mainly related to glycolysis. However, under the 35 °C temperature stress, 'Renong No.1' responded by redistributing riboflavin and betaine in vivo and the most obvious metabolic pathway of 'Jinhuang' enrichment was pyrimidine metabolism, which had undergone complex main body formation and extensive regulatory processes. The changes of metabolites of different varieties under low temperature and high temperature stress were different. Among them, flavonoids or flavonoid derivatives were included in class A (216 metabolites), C (163 metabolites) and D (233 metabolites) metabolites, indicating that flavonoid metabolites had an obvious regulatory effect on mango pollen metabolism under different temperature stress. The present results provide valuable information for reproductive biology studies and breeding in mango, in particular, the selection and breeding of the most suitable varieties for different production areas.

Breeding biology of mimetic species based on secondary data sources should address misidentifications: the case of the lesser kiskadee Philohydor lictor (Aves: Tyrannidae)

ABSTRACT Philohydor lictor is a Neotropical tyrant flycatcher that belongs to a kiskadee-like mimetic system. This system encompasses seven genera with at least one species with strikingly similar plumage patterns, in which smaller species mimic larger species to deceive predators. The reproduction of P. lictor is poorly known, and misidentification of its nests and eggs with other species with similar plumage may be common, creating confusion between them. Here, we aim to summarise the knowledge about its reproductive biology and highlight the common pitfalls in gathering information on mimetic species in citizen science, literature, and museum databases. We assembled 106 reproductive records from between 1898 and 2023, of which 49 were from citizen science, 37 were from the literature, and 20 were from museum egg collections. Most reproductive records were from Panama (31.3%, N = 26) and Brazil (25.3%, N = 21). Egg-laying mainly occurred in the first half of the year and peaked when monthly total precipitation was between 150 and 300 mm (40%, N = 16). Nests were loose cups placed on vegetation near water and built with dry twigs, roots, and tendrils lined with fine twigs. Eggs from museum collections measured 20.9 × 16.1 mm (N = 23). Misidentified records comprised 21.7% (N = 23) of total breeding records and mainly occurred in <1935 museum egg collections. Misidentifications included records of domed nests, eggs larger than expected for the species’ body size, and records from outside the species’ range. These results stress that studies of reproductive biology of mimetic species based on citizen science, literature, and museum datasets are not straightforward, and data should be refined by validation procedures. These validations should include verification that records fall inside the species’ geographic range, include correct description of nests, and match egg size with adult body size.

Blood Sampling and Hormone Measurement for Determining the Stage in the Ovarian Cycle in Marmosets.

Common marmosets are small New World monkeys. Since many of their biological mechanisms are similar to those of humans, marmosets are potentially useful for medical and human biology research across a range of fields, such as neuroscience, regenerative medicine, and development. However, there is a lack of literature describing methods for many basic experiments and procedures. Here, detailed methods for determining the levels of sex hormones (progesterone, estradiol, and chorionic gonadotropin) in marmosets are described. The measurement of these hormones enables the prediction of the stage in the ovarian cycle, which is typically 26-30 days in marmosets; accurate determination is essential for the harvesting of oocytes/zygotes at the correct time point and for the preparation of host females for the generation of genetically modified marmosets. Additionally, the measurement of sex hormone levels is useful for endocrinology, ethology, early development, and reproductive biology studies. This protocol provides a detailed description of the methods for blood sampling from the femoral vein, separation of plasma for hormone measurement, measuring chorionic gonadotropin levels using urine and plasma, resetting the ovarian cycle using injections of a prostaglandin F2α analog to shorten and synchronize the cycle, and promoting follicular growth and ovulation by injecting follicle-stimulating hormone and chorionic gonadotropin. Using these protocols, the stages in the ovarian cycle can be determined for the timely collection of oocytes/zygotes.

Investigating the reproductive strategies of Deuterocohnia meziana (Bromeliaceae), an endangered and restricted species from South American rocky outcrops.

Studies of reproductive biology and resources availability to floral visitors by plant species are important to understand the plant-pollinator interactions that drive species adaptation. We aim to understand the relationship between reproduction mechanisms of Deuterocohnia meziana (Bromeliaceae) and pollinators. The species occurs in Bolivia and Paraguay, and it is the only species of the genus found in Brazil, where it is restricted to ironstone outcrops. These areas are currently threatened by the iron mining industry. Additionally, they face risks from fire occurrence and grazing by cattle. We analyzed the floral biology, reproductive system, phenology, and pollination ecology of a natural population of Deuterocohnia meziana, from ironstone outcrops in Brazil. The species exhibits diurnal anthesis, with stigma receptive throughout anthesis, and 77% of pollen viability. Deuterocohnia meziana produces relatively large amounts of nectar, especially early in the morning (32.8 ± 9.4μl), with a mean sugar concentration of 23.5 (± 3.2) ºBrix. It is self-incompatible with a peak flowering occurring in August (dry season), although flowers are observed continuously throughout the year. The species exhibits two types of inflorescences, young and mature, among which an average of 13.1 and 3.6 flowers open per day, respectively. Hummingbirds and bees are the effective pollinators, although butterflies and ants also visit D. meziana flowers. The species is reliant on exogenous pollen and pollinators for fruit set. The continuous conservation of D. meziana populations and their communities is essential for preserving plant-pollinator mutualism and the floral community adapted to ironstone outcrops.

The seed morphospace, a new contribution towards the multidimensional study of angiosperm sexual reproductive biology.

The evolutionary success of flowering plants is associated with the vast diversity of their reproductive structures. Despite recent progress in understanding angiosperm-wide trends of floral structure and evolution, a synthetic view of the diversity in seed form and function across angiosperms is lacking. Here we present a roadmap to synthesise the diversity of seed forms in extant angiosperms, relying on the morphospace concept, i.e. a mathematical representation which relates multiple traits and describes the realised morphologies. We provide recommendations on how to broaden the range of measurable traits beyond mass, by using key morphological traits representative of the embryo, endosperm, and seed coat but also fruit attributes (e.g., dehiscence, fleshiness). These key traits were used to construct and analyse a morphospace to detect evolutionary trends and gain insight into how morphological traits relate to seed functions. Finally, we outline challenges and future research directions, combining the morphospace with macroevolutionary comparative methods to underline the drivers that gave rise to the diversity of observed seed forms. We conclude that this multidimensional approach has the potential, although still untapped, to improve our understanding of covariation among reproductive traits, and further elucidate angiosperm reproductive biology as a whole.

Reproductive features of data-deficient yellowfin snapper, Lutjanus xanthopinnis (Actinopterygii: Eupercaria: Lutjanidae), from east-coast of Peninsular Malaysia: Implications for sustainable fisheries management

Understanding the reproductive biology of fishes is crucial to making accurate and scientifically sound recommendations for fisheries management. The presently reported study is the first to report the reproductive characteristics of the data-deficient and recently described yellowfin snapper, Lutjanus xanthopinnis Iwatsuki, Tanaka et Allen, 2015, collected from the eastern South China Sea, Malaysia. A total of 572 fish specimens were sampled monthly from March 2022 to April 2023 using a gillnet and a trawl net. Subsequently, these specimens were measured and weighed. Their total length (TL) ranged from 15.3 to 26.8 cm (19.25 ± 2.04 cm; mean ± SD). Their body weight (WB) ranged from 53.5 g to 279.7 g (114.5 ± 40.3 g; mean ± SD). For the reproductive biology study, the following parameters were determined: the sex ratio, gonadosomatic index (GSI), hepatosomatic index (HSI), spawning period, fecundity, condition factor (K), length at maturity, and the gonadal maturity stages. In the sex ratio, males (M) were significantly dominant over females (F) (M:F = 1:0.75) (χ2 = 11.18). Consequently, the monthly mean GSI of pooled sex revealed a consistent trend from January to August, indicating spawning seasons with peak periods in March and April. The batch fecundity of 67 mature females (16.0–25.2 cm TL; 64.5– 279.3 g W), was determined to range from 16 405 to 94 357 oocytes. The fecundity increased with gonad weight in contrast to weight and length. The length at first maturity of females and males was 14.53 and 20.56 cm, respectively. Females matured earlier than males. Macroscopic and histological examination of gonads revealed monthly variation in the ratio of gonad stages for males and females. This study offers crucial data on the reproductive biology of L. xanthopinnis, which will help with sustainable fishery management in this area and can be used as a reference for the management of similar fish populations in other regions of the world.

Gonadosomatic-hepatosomatic index and sex ratio of beardless barb (Cyclocheilichthys apogon) from Lebak Kalong Floodplain, Ogan Komering Ilir, South Sumatra, Indonesia

The beardless barb (Cyclocheilichthys apogon) is one of the freshwater fish species native to Indonesia. Gonadosomatic index (GSI), hepatosomatic index (HSI), and sex ratio are parameters in the study of fish reproductive biology. The aim of this study was to calculate the gonadosomatic index, hepatosomatic index and sex ratio of C. apogon from the Lebak Kalong Floodplain, Ogan Komering Ilir Regency. A total of 30 C. apogon samples were used in this study. C. apogon samples were dissected to remove gonadal organs and liver organs from the abdominal cavity. The gonads and liver were weighed for the calculation of GSI and HSI, respectively. The results showed that the gonadosomatic index of female C. apogon ranged from 3.33% to 15.83%, and that of males ranged from 1.04% to 7.27%. The hepatosomatic index of female C. apogon ranged from 0.20% to 2.86%, and that of male fish ranged from 0.34% to 1.92%. The gonadosomatic index and hepatosomatic index of female C. apogon were heavier than those of males. The sex ratio was 1:1 (♂:♀). Knowledge of the gonadosomatic index, hepatosomatic index, and sex ratio can be used to determine the reproductive biology aspects of C. apogon. Further studies should be conducted to obtain more information on the reproductive aspects of C. apogon.

Spatio-temporal patterns of ovarian development and VgR gene silencing reduced fecundity in parthenogenetic Artemia

The halophilic zooplankton brine shrimp Artemia has been used as an experimental animal in multidisciplinary studies. However, the reproductive patterns and its regulatory mechanisms in Artemia remain unclear. In this study, the ovarian development process of parthenogenetic Artemia ( A. parthenogenetica ) was divided into five stages, and oogenesis or egg formation was identified in six phases. The oogenesis mode was assumed to be polytrophic. We also traced the dynamic translocation of candidate germline stem cells (cGSCs) using EdU labelling and elucidated several key cytological events in oogenesis through haematoxylin and eosin staining and fluorescence imaging. Distinguished from the ovary structure of insects and crustaceans, Artemia germarium originated from ovariole buds and are located at the base of the ovarioles. RNA-seq based on five stages of ovarian development identified 2657 upregulated genes related to reproduction by pair-to-pair comparison. Gbb , Dpp , piwi , vasa , nanos , VgA and VgR genes associated with cGSCs recognition and reproductive development were screened and verified using qPCR. Silencing of the VgR gene in A. parthenogenetica ( Ap-VgR ) at ovarian development Stage II led to a low level of gene expression (less than 10%) within 5 days, which resulted in variations in oogenesis-related gene expression and significantly inhibited vitellogenesis, impeded oocyte maturation, and eventually decreased the number of offspring. In conclusion, we have illustrated the patterns of ovarian development, outlined the key spatio-temporal features of oogenesis and identified the negative impacts of VgR gene knockdown on oogenesis using A. parthenogenetica as an experimental animal. The findings of this study also lay a foundation for the further study of reproductive biology of invertebrates.

Oocyte may be a promising target for the study of reproductive biology and medicine

The reproduction and evolution of organisms is an eternal issue worthy of research or exploration. Homo sapiens, also known as human beings, is the most widely distributed terrestrial mammal species and lives on every continent on the earth, and also facing the issue of reproduction and evolution. This work is to propose a new target for the study of reproductive biology and medicine. Evidence indicated that oocyte may be a promising target for the study of reproductive biology and medicine. We posit that the hypothesis above may play an important role in the study of reproductive biology and medicine; which can be reflected in the following: (1) It will help to reveal the development/maturation process of oocytes, and to discover the biochemical regulatory mechanisms of oocyte growth and maturation; (2) It will help to explain the evolution and species difference of oocytes; (3) It will be helpful to research and develop novel assisted reproductive technologies (ART); and (4) It will help to solve the infertility of human beings. Therefore, we believe that the hypothesis above is worth further validated in the future, and it will help to promote our understanding of the biological basis of oocyte biology, reproductive biology and medicine.

(2949) Proposal to conserve the name Quercus pacifica Nixon &amp; C.H. Mull. against Q. pacifica Knowlt. (Fagaceae)

(2949) Quercus pacifica Nixon & C.H. Mull. in Novon 4: 391. 30 Nov 1994 [Angiosp.: Fag.], nom. cons. prop. Typus: U.S.A., California, Santa Barbara Co., rocky slope E. of Pelican Bay, Santa Cruz Island, alt. 100 ft., Clokey 4893 (BH-CHM). (H) Quercus pacifica Knowlt. in Rep. (Annual) U.S. Geol. Surv. 20(3): 43, t. 4, fig. 9, 10. 1900 [Foss.], nom. rej. prop. Typus: non designatus. In 1994, K.C. Nixon and C.H. Muller recognized the taxonomic distinctness of populations of shrubby oaks on three islands off the coast of southern California (Santa Cruz, Santa Catalina, and Santa Rosa Islands), and described them as a new species, Quercus pacifica Nixon & C.H. Mull. (in Novon 4: 391–392. 1994) with the holotype cited above. Subsequent genetic research has confirmed the distinctness of this taxon (Backs & Ashley in Amer. J. Bot. 103: 2115–2125. 2016). The taxon and the habitat are both endangered, so the taxon is subject to monitoring and conservation efforts across its limited range. Unfortunately, an earlier Quercus pacifica was published by F.H. Knowlton (in Rep. (Annual) U.S. Geol. Surv. 20(3): 43, t. 4, fig. 9, 10. 1900), based on Eocene fossils from Oregon, U.S.A. This was in a short paper, published as part of a geological report on a mining district in southern Oregon. Roland W. Brown (in J. Wash. Acad. Sci. 46: 104–108. 1956) subsequently excluded Q. pacifica Knowlt. from Fagaceae and made the new combination Caesalpinia pacifica (Knowlt.) R.W. Br. The placement in Fabaceae subfam. Caesalpinioideae, though not the assignment to Caesalpinia, was supported by Herendeen & Dilcher (in Amer. J. Bot. 78: 1–12. 1991). The priority of Knowlton's name over Q. pacifica Nixon & C.H. Mull. was first noted by Piers Trehane in the International Oak Society Checklist (http://www.oaknames.org/search/fullname.asp?id=506), where he said, “Nixon's name needs to be proposed for conservation”, but Trehane died before publishing a proposal. The name Quercus pacifica Nixon & C.H. Mull. has been used for this species in all recent references that deal with oaks of the region (e.g., Nixon & Muller in FNA Ed. Comm., Fl. N. Amer. N. Mex. 3: 471–506. 1997; Junak & al. in Barbour & al., Terrestr. Veg. California, ed. 3: 229–252. 2007; Tucker in Baldwin & al., Jepson Manual, ed. 2: 803–808. 2012; Jerome & al., Red List US Oaks. 2017). The species is considered endangered (Jerome & al., l.c.), so it is subject to monitoring and conservation efforts across its limited range, resulting in a plethora of studies, including studies of genetic structure and reproductive biology (Knapp in Standiforth & al., Proc. Fifth Symp. Oak Woodlands. 2002; Knapp, Oak Ecosyst. Restorat. Santa Catalina Island, California. 2011; in Monogr. W. N. Amer. Naturalist 7: 421–434. 2014; Pesendorfer & al. in Monogr. W. N. Amer. Naturalist 7: 246–259. 2014; in Curr. Zool. 63: 363–367. 2017; Backs & Ashley, l.c.) and conservation plans, all of which use the name Q. pacifica. Furthermore, the species is locally dominant in its very limited range, so its name forms part of the formal names of several communities in the widely used classification of California vegetation by Sawyer & al. (Manual California Veg., ed. 2. 2009), including the “Quercus dumosa – Quercus pacifica Alliance” and six formally named Associations. These vegetation type names are widely used in ecological and conservation studies of all groups of organisms, and all would have to be changed if the name of the co-dominant, Q. pacifica, were to change. Replacing Q. pacifica Nixon & C.H. Mull. with another name would therefore cause significant confusion among many active conservation programs as well as in the scientific literature. On the other hand, there is no reason to preserve the name Q. pacifica Knowlt., the basis of which is actually a legume. Conservation of Q. pacifica Nixon & C.H. Mull. will not affect the name Caesalpinia pacifica (Knowlt.) R.W. Br.; although Q. pacifica Knowlt. cannot be the correct name for a taxon when a later homonym has been conserved, it remains a legitimate name, and may serve as basionym for another combination (Art. 56 Note 1 of the ICN, Turland & al. in Regnum Veg. 159. 2018). ATW, https://orcid.org/0000-0002-7983-6374

Editing the Genome of the Golden Hamster (Mesocricetus auratus).

The golden (Syrian) hamster (Mesocricetus auratus) is a small rodent belonging to the Cricetidae family. Golden hamsters have several unique characteristics that are advantageous in the study of reproductive and developmental biology: a highly stable 4-day estrous cycle, a high responsiveness to conventional superovulation methods, and a shortest gestation period (16days) known among eutherian mammals. Besides these advantages, the technical ease of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in this species has contributed much to our understanding of the basic mechanisms of mammalian fertilization. However, the exceptionally strong in vitro developmental block of hamster embryos, especially at the two-cell stage, has hampered the production of genetically modified hamsters, which has resulted in limited use of this species for biomedical research. However, the recently developed in vivo genome editing method (improved genome editing via oviductal nucleic acid delivery, i-GONAD) has overcome this shortcoming and made production of gene-edited hamsters much easier than before. This method has the potential to provide a means of reexamining genes whose functions cannot be identified using mouse models, thus leading to the better understanding of gene functions in mammals. In this chapter, we present our procedure for editing the genome of the golden hamster using i-GONAD.

A review of reproduction in the seaweed genus Fucus (Ochrophyta, Fucales): Background for renewed consideration as a model organism

The genusFucusdominates the intertidal and shallow subtidal rocky reefs of the North Atlantic and also is commonly found in the intertidal of the North Pacific. It likely diversified 12.2-2.7 mya into two genetically distinct lineages: Lineage 1 with one species in the North Pacific and two in the North Atlantic; and Lineage 2 found only in the North Atlantic (one species recently introduced into the North Pacific). With 10 accepted species,Fucusspp. (and the Fucales) are unique among algae in having a diplontic life cycle, whereby the only haploid stage is the single-celled gamete. Further,Fucusspp. produce eight eggs in each oogonium; have hermaphroditic and dioecious species in each lineage; display sperm:egg ratios differing by more than one order of magnitude; have synchronized and predictable release of gametes; are capable of self- and/or cross- fertilization and asexual (fragmentationviaadventitious branching) reproduction; readily hybridize in culture, as well as the field; and form ecads (free-living individuals with morphological variability linked to habitat) by hybridization or polyploidy. Consequently, the genus is an excellent model for a variety of studies in reproductive biology, employing laboratory and field manipulations as well as detailed genetic studies using the molecular ‘omics’. We review here the relevant literature in order to fully understand and appreciate the unique opportunities thatFucusspp. provide as model organisms for future studies of reproduction.

Genome editing in mice and its application to the study of spermatogenesis

Gene modification technology has long been beneficial for unraveling the mystery of biological phenomena. Thus, the advent of the clustered regularly interspaced short palindromic repeats (CRISPR)/ CRISPR-associated (Cas) 9 system was a game-changer in biological research because of its efficiency and simplicity of design. This review article first describes a brief guideline of gRNA design and the methods to incorporate the CRISPR/Cas9 system into zygotes. Then, we will also discuss the application of this technology to the study of male reproductive biology, including knock-out (KO) phenotypical screening of genes expressed in the male reproductive tissues.

Competitive Sperm-Marked Beetles for Monitoring Approaches in Genetic Biocontrol and Studies in Reproductive Biology.

Sperm marking provides a key tool for reproductive biology studies, but it also represents a valuable monitoring tool for genetic pest control strategies such as the sterile insect technique. Sperm-marked lines can be generated by introducing transgenes that mediate the expression of fluorescent proteins during spermatogenesis. The homozygous lines established by transgenesis approaches are going through a genetic bottleneck that can lead to reduced fitness. Transgenic SIT approaches have mostly focused on Dipteran and Lepidopteran pests so far. With this study, we provide sperm-marked lines for the Coleopteran pest model organism, the red flour beetle Tribolium castaneum, based on the β2-tubulin promoter/enhancer driving red (DsRed) or green (EGFP) fluorescence. The obtained lines are reasonably competitive and were thus used for our studies on reproductive biology, confirming the phenomenon of ‘last-male sperm precedence’ and that the spermathecae are deployed for long-term sperm storage, enabling the use of sperm from first mating events even after secondary mating events for a long period of time. The homozygosity and competitiveness of the lines will enable future studies to analyze the controlled process of sperm movement into the long-term storage organ as part of a post-mating cryptic female choice mechanism of this extremely promiscuous species.

Why empresses have more sons? Maternal instant social condition determines it

Sexual selection echoed by the sex ratio is a critical issue in evolution and reproductive biology studies, and the second sex ratio (sex ratio at birth, SRB) is an important evaluation indicator for sex regulation. However, broad debates on sex ratio at birth exist due to the lack of a clear spatiotemporal genealogical database. This study explicitly tests the Trivers and Willard’s hypothesis stating that parents with good social conditions tend to show a male-biased SRB. Using a database of Chinese imperial families from 211BC to 1912 (2142 years) which avoids the spatiotemporal confusion of data thanks to its clear boundaries and long timespan, we found that a proportion of males at birth was 0.54. In particular, the results indicate that the empresses generated a significantly higher male-biased SRB than the concubines within the imperial harems (0.61 vs 0.53), while the SRB of concubines was not higher than ordinary people (0.53 vs 0.52). A significant difference of SRB before and after empress coronation (0.48 vs 0.65) was detected, indicating that the change to a higher social status is the leading cause of a biased SRB. These findings suggest that mothers with privileged instant social conditions tend to generate more boys than girls. In other words, a higher maternal social rank during the conception period, instead of rich resources, forms the primary mechanism regulating the SRB.Significance statementAdaptive sex ratio has been a debatable topic difficult to clearly verify since the publication of Trivers and Willard Hypothesis in 1973, which proposes that parents who have good conditions should produce more male offspring. The one reason is that the validity and sample size of the databases used contained unavoidable confounding noise, both genealogically and genetically. To overcome these issues, we specifically compiled a historical database of Chinese imperial families, which are characterized by a confined mating harem and unique eunuch system, guaranteeing biological and genetic purity with precise genealogical relationships and genetic linkages between the parents and the offspring. Thus, this is an extraordinary effort to clarify the hypotheses proposed by TWH and other hypotheses.

PRSS37 deficiency leads to impaired energy metabolism in testis and sperm revealed by DIA-based quantitative proteomic analysis.

Our previous studies have reported that a putative trypsin-like serine protease, PRSS37, is exclusively expressed in testicular germ cells during late spermatogenesis and essential for sperm migration from the uterus into the oviduct and sperm-egg recognition via mediating the interaction between PDILT and ADAM3. In the present study, the global proteome profiles of wild-type (wt) and Prss37-/- mice in testis and sperm were compared employing data independent acquisition (DIA) technology. Overall, 2506 and 459 differentially expressed proteins (DEPs) were identified in Prss37-null testis and sperm, respectively, when compared to control groups. Bioinformatic analyses revealed that most of DEPs were related to energy metabolism. Of note, the DEPs associated with pathways for the catabolism such as glucose via glycolysis, fatty acids via β-oxidation, and amino acids via oxidative deamination were significantly down-regulated. Meanwhile, the DEPs involved in the tricarboxylic acid cycle (TCA cycle) and oxidative phosphorylation (OXPHOS) were remarkably decreased. The DIA data were further confirmed by a markedly reduction of intermediate metabolites (citrate and fumarate) in TCA cycle and terminal metabolite (ATP) in OXPHOS system after disruption of PRSS37. These outcomes not only provide a more comprehensive understanding of the male fertility of energy metabolism modulated by PRSS37 but also furnish a dynamic proteomic resource for further reproductive biology studies.

Chromosomal and reproductive barriers among three species of Cleome L. from Ile‐Ife, Nigeria

Cleome rutidosperma DC, C. viscosa L. and C. gynandra L. have been observed to sometimes grow sympatrically in Ile‐Ife, Nigeria. Here, we investigated the genetic relationship and reproductive barriers among these species through cytological, reproductive biology and hybridization studies. A chromosome number of 2n = 2x = 34 was observed in C. gynandra, while 2n = 2x = 20 was documented in C. viscosa and C. rutidosperma. Two simultaneous cytokineses were observed in meiotic chromosomes of all three species and no chromosomal aberrations were observed. The seed germination percentage increased over the course of 12 months in C. gynandra, while a loss of seed viability was observed with increasing storage time in C. viscosa and C. rutidosperma. Reciprocal crosses were characterized by heavy flower drops and embryo abortion and no viable F1 seed was obtained. The lowest percentage of fruit set, 4% and 2.3%, was observed in C. viscosa × C. rutidosperma and C. viscosa × C. gynandra, respectively. The results demonstrate that although the species appear to share the same pollinators, strong post‐zygotic reproductive isolation mechanisms have been established, thereby making the exchange of genes difficult. In addition, the species‐specific inherent mechanisms of seed dormancy might have a strong influence on the distribution of these species

Reproductive Biology of Rheum webbianum Royle, a Vulnerable Medicinal Herb From Alpines of North-Western Himalaya.

Information on reproductive biology and pollination ecology studies of threatened plants are essential to develop strategies for their sustainable utilization and effective conservation. As such, these studies were conducted on Rheum webbianum, a high-value “vulnerable” medicinal herb of the north-western Himalaya. This species presents a unique mode of reproductive behavior through the involvement of different floral events, including the movement of reproductive organs. The plants survive extremely cold conditions through underground perennating rhizomes that sprout into juvenile shoots with the onset of the favorable climatic conditions. The peduncle arises from the axils of the radical leaves, bearing a globular collection of densely arranged hermaphrodite flowers with temporally separated male and female phases; the male phase precedes the female phase (protandry). Anther dehiscence and stigma receptivity is post-anthesis. Anthers dehisce longitudinally along margins, liberating a large mass of spherical and tricolpate pollen with spinulose exine. Pollen viability decreased to < 10% on day 9. Pistil is tristylous, with each style terminating into a fan-shaped stigma lobe. The pollen receptive surface of each stigmatic lobe remains incurved at an angle of 360° and shows upward movement after anthesis, forming a funnel-like structure at an angle of 180° with respect to the ovary. Pollination syndrome is ambophilous. Spontaneous autogamy or geitonogamy to a certain extent is achieved in this species due to the arrangement of flowers in the inflorescence and overlapping of male and female reproductive phases among them. Incurved stigmatic lobes and outward movement of stamens too facilitate outcrossing. Pollen/ovule ratio estimates, results of pollination experiments on breeding behavior, outcrossing, and self-compatibility indices demonstrated that plants are self-compatible and cross-fertile.

Pollen Production of Selected Grass Species in Russia and India at the Levels of Anther, Flower and Inflorescence.

Grasses produce large amounts of pollen and are among the main causes of pollen allergy worldwide. Quantification of the roles of individual grass species in airborne pollen is an important task, because morphologically indistinguishable pollen grains of different species may differ in allergenicity. This requires knowledge of the pollen production of individual grass species; however, accumulated data are insufficient in this respect. Attempting to fill this gap, we studied pollen production per inflorescence in 29 grass species which are widespread in Middle Russia and India. Pollen production per inflorescence is determined by the number of grains per anther, the number of flowers in a spikelet and the number of spikelets per inflorescence, with the latter parameter being the most variable. We support the hypothesis that pollen production per inflorescence differs significantly between annual and perennial grasses. The greater pollen production of perennials can be interpreted as a tendency to guarantee cross-fertilization of species with self-incompatibility. The inferred pollen/ovule (P/O) ratios suggest the occurrence of facultative xenogamy in all annuals and obligate xenogamy in most perennials in the present dataset, though some self-incompatible annuals exist outside our sampling. Earlier data indicated that the P/O ratio of the annual cereal crop rye (Secale cereale) is higher than in any annual or perennial species sampled here. A ratio of pollen production to seed set (P/S ratio) is suggested to be another efficient parameter in reproductive biology of grasses. We highlight a need for detailed studies of reproductive biology in grasses that include both pollen and seed production. We found a correlation between pollen production per anther and anther length. A rough approximation of c. 1000 pollen grains per 1 mm of the length of an anther provides an instrument for estimates of pollen production in plant communities.

Embryos, cancers, and parasites: Potential applications to the study of reproductive biology in view of their similarity as biological phenomena.

BackgroundAt present, there are so many living things on the earth. Most of these organisms have a reproductive strategy called sexual reproduction. Among organisms that reproduce sexually, mammals have an extremely complex and seemingly unnatural method of reproduction, or viviparity.MethodsAs an approach to understanding the nature of viviparity, the author have tried to outline the common life phenomena of embryos, cancers, and parasites based on the literature to date, with internal parasites as the keyword.Main findingsEmbryo, cancer, and parasite are constituted as a systemic interaction with the host (mother). Based on these facts, the author proposed the hypothesis that in the case of mammals, "the fetus is essentially harmful to the mother", and that the parasitic fetus grows by skillfully evading the mother's foreign body exclusion mechanism.ConclusionComparative studies of "embryos", "cancers", and "parasites" as foreign bodies have the potential to produce unexpected discoveries in their respective fields. It is important to consider the evolutionary time axis that the basic structure of our mammalian body arose over 200 million years from the Mesozoic Triassic, the period immediately after the Paleozoic Era, when life on Earth became massively extinct.