Gonadal Development Research Articles

Improper dietary protein to carbohydrate ratio causes abnormal visceral fat deposition, hampering gonadal development and breeding performance in Labeo Catla female

The availability of balanced diet is critical for reproductive success in fish. A feeding trial on Labeo catla females was carried out in earthen pond to assess the effect of different dietary protein to carbohydrate ratio on gonad maturation and breeding performance. Three feed D-I (Feed-I), D-II (Feed-II) and D-III (Feed-III) were formulated with varying ratio of Ground Nut Oil Cake (GNOC) and rice bran (2:1, 1:1 and 1:2) and fed for 120 days. To assess the gonad maturation events, GSI VSI, breeding, fatty acid analysis, sex hormone profiling, cholesterol, triglyceride and histological examinations were conducted. Fish groups fed with D-III exhibited the highest VSI and visceral fat (VF) deposition, followed by those fed with D-I, whereas groups fed with D-II showed significantly lower levels (P<0.05). The result of GSI was completely opposite to values of VSI. Ovarian histology showed less number of mature oocytes in D-I & D-III treatments and more mature oocytes in D-II. Breeding results showed that fishes fed with D-I and D-III hampered gonad maturation whereas fish fed with D-II responded towards spawning, fertilization, and hatching. Increased levels of testosterone, estradiol, and vitellogenin (Vtg) were observed in the D-II fed group whereas increased level of progesterone was observed in D-I fed group followed by D-II and D-III. Serum cholesterol was higher in the D-III and D-I group. Visceral fat accumulation prior to ovarian maturation is a normal phenomenon in this species which serves as a lipid reservoir required for the later transfer to the gonad as yolk or is utilized as an energy source for gonad maturation. However higher level of protein or carbohydrate in the diet disrupted normal gonad maturation and lead to abnormal visceral fat accumulation, sex steroid level, failure in spawning response and seed production.

Tracking gonadal development in fish: An in vivo MRI study on polar cod, Boreogadus saida (Lepechin, 1774).

Magnetic resonance imaging (MRI) was applied to determine the sex of polar cod (Boreogadus saida Lepechin, 1774) (Actinopterygii: Gadidae) and to follow the gonadal development in individual animals over time. Individual unanaesthetised fish were transferred to a measurement chamber inside a preclinical 9.4T MRI scanner and continuously perfused with aerated seawater. A screening procedure at an average of 3.5h, consisting of a set of MRI scans of different orientations, was repeated every 4 weeks on the same set of reproducing B.saida (n= 10) with a body length of about 20 cm. Adapted multi-slice flow-compensated fast low-angle shot (FcFLASH) and rapid acquisition with relaxation enhancement (RARE) protocols with an in-plane resolution of 313 μm and an acquisition time of 2.5min were used to visualise the morphology of various organs, including the gonads within the field of view (FOV). The MR images provided high resolution, enabling specific sex determination, calculation of gonad volumes, and determination of oocyte sizes. Gonad maturation was followed over 4 months from November 2021 until shortly before spawning in February 2022. The gonad volume increased by 2.3-25.5% for males and by 11.5-760.7% for females during the observation period. From October to February, the oocyte diameter increased from 427 μm (n= 1) to 1346 ± 27 μm (n= 4). Interestingly, individual oocytes showed changes in MR contrast over time that can be attributed to the morphological development of the oocytes. The results fit well with previous literature data from classical invasive studies. The presented approach has great potential for various ecophysiological applications such as monitoring natural or delayed development of internal organs or sex determination under different environmental conditions.

Analysis of the Molecular Mechanism of Energy Metabolism in the Sex Differentiation of Chickens Based on Transcriptome Sequencing.

The determination of sex in mammals is established and controlled by various complex mechanisms. In contrast, sex control in poultry remains an unresolved issue. In this study, RNA-sequencing was conducted for male gonads and ovarian tissues in chicken embryos of up to 18.5 days to identify metabolic factors influencing male and female sex differentiation, as well as gonadal development. Our results reveal that PKM2, a critical glycolysis-related protein, plays a significant role in chicken sex differentiation via PPARG, a crucial hormone gene. We propose that our discoveries bolster the notion that glycolysis and oxidative phosphorylation function as antecedent contributors to sexual phenotypic development and preservation.

Comparative histological analysis of gonad development between autotriploid (Crassostrea gigas and C. angulata) and allotriploid oysters

China has the highest oyster yield in the world, with Crassostrea gigas and C. angulata being the two most productive oysters species. The hybrid triploid of Crassostrea gigas and C. angulata exhibits good heat resistance and can mitigate the plight of mass mortality of Crassostrea gigas in northern China caused by high temperature and spawning during the summer. Additionally, triploid oysters have reduced fecundity, which allows the energy typically used for gonad development to be redirected to somatic cell growth, resulting in better taste and lower mortality during the reproductive season. Therefore, it is essential to study the detailed gonad development of hybrid triploid oysters. This study compared the gonad development between autotriploids (TGG-diploid C. gigas ♀ × tetraploid C. gigas ♂) and allotriploids (TAG-diploid C. angulata ♀ × tetraploid C. gigas ♂) during the breeding season. Results showed that the female proportion of TGG increased gradually with rising temperature, reaching a peak of 57.1% in August, whereas the proportion of females in TAG was lower, with males accounting for >50% from June to August 2023. Histological analysis revealed that the proportion of female α (producing many oocytes) increased with gonad development, peaking for TGG female α in July and for TAG female α in September. Moreover, the number of sperm in male TAG gonadal tubules was less than in male TGG, and more apoptotic cells were observed in the ultrastructure of male TAG gonad, which was confirmed by apoptosis experiment. Based on these results, it is suggested that the gonad development of female and hermaphrodite TAG were delayed compared with TGG, and the level of sterility in male TAG should be higher than in male TGG.

Structure and function of vasa gene in gonadal gametogenesis of Pacific abalone

Pacific abalone (Haliotis discus hannai) is a marine gastropod mollusc with significant economic importance in both global fisheries and aquaculture. However, studies exploring the gonadal development and regulatory mechanisms of Haliotis discus hannai are limited. This study aimed to explore whether the vasa gene acted as a molecular marker for germ cells. Initially, the vasa gene was successfully cloned using the cDNA-end rapid amplification technique. The cloned gene had a 2478-bp-long open reading frame and encoded 825 amino acids. Then, a recombinant expression vector was constructed based on the Vasa protein, and an 87-kDa recombinant protein was prepared. Subsequently, a polyclonal antibody was prepared using the purified recombinant protein. The enzyme-linked immunosorbent assay (ELISA) confirmed the titer of the antibody to be ≥512 K. The immunohistochemical analysis revealed that Vasa was widely expressed in oogonia, Stage I oocytes, spermatogonia, and primary spermatocytes. The specific expression of Vasa in the hermaphroditic gonads of abalone was assessed using western blotting to investigate the effects of different photoperiods (12 L:12D, 24 L:0D, 18 L:6D, and 6 L:18D) on the gonadal development of abalone (P < 0.05), with higher expression levels observed in the ovarian proliferative and spermary maturing stages compared with other developmental stages (P < 0.05). Additionally, Vasa exhibited the highest expression in the spermary and ovary under a photoperiod of 18 L:6D (P < 0.05). These data demonstrated the key role of Vasa in developing germ cells in abalone. They shed light upon the molecular mechanism through which the photoperiod influenced Vasa expression and regulated gonadal development in abalone. The findings might provide theoretical references for analyzing the differentiation pattern of abalone germ cells and the genetic improvement and conservation of germplasm resources.

Characterization of sexual size dimorphism in mandarin fish and association with igfbp-5a/b regulation.

Mandarin fish (Siniperca chuatsi) is an important cultured fish in East Asia that shows sexual size dimorphism (SSD), with females growing faster than males when reaching marketable size. However, the regulatory mechanism of SSD is not clear. To characterize SSD of mandarin fish and its association with gh/igf1/igfbp-5 expression, gonadal developmental atlas of the females and the males were described, and growth parameters and serum levels of E2 and T, as well as the relative expression levels of gh, igf1, and igfbp-5a/b mRNAs, were determined. The results showed that the logistic growth equation of body mass and total length of female and male were W(♀) = 667.57/(1 + e^(4.19 - 1.24*t)), W(♂) = 582.71/(1 + e^(4.07 - 1.27*t)), L(♀) = 31.47/(1 + e^1.95 - 1.08*t)), L(♂) = 26.20/(1 + e^(2.56 - 1.5*t)). The month of inflection points for body mass for females and males were 3.37 mph and 3.20 mph, respectively, when the body mass were 333.79g and 291.36g. The month of inflection points for total length growth were 1.80 mph and 1.70 mph, respectively, when the total length were 18.52cm and 16.28cm. At 1.5-2.0 mph, SSD was not clearly demonstrated. At 3.0 mph, the body mass of the females was significantly higher than that of the males (P < 0.05), Serum E2, brain gh, and liver igf1 expression of the females was significantly higher than that of the males (P < 0.05); T content of the males was significantly higher than that of the females (P < 0.05). At 4.0months of age, the body mass of the females was highly significantly higher than that of the males (P < 0.01), Serum E2, brain gh, and liver igf1 expression of the females was highly significantly higher than that of the males (P < 0.05); T content of the males was significantly higher than that of the females (P < 0.05). With the continuous development of gonads, muscle and liver igfbp-5a and -5b expression generally tend to increase in females and males, while igfbp-5a showed a gradual increasing trend, and igfbp-5b expression showed a trend of decreasing and then increasing. Male igfbp-5a/b expression was significantly higher than female at the age of 3.0-4.0months (P < 0.05). This work verified that the females had faster growth rate since 3.0 mph compared to the males, which may be related to higher E2 levels in females leading to higher igf1 level, through inhibition of igfbp-5a/b expression.

Effect on growth, gonad development, health and disease resistance against Aeromonas hydrophila of Origanum minutiflorum essential oil in Cyprinus carpio

This study investigated the effects on growth performance, histopathology, intestinal histomorphology, antioxidant activity, serum biochemical parameters, and disease resistance against A. hydrophila of carp fed with oregano essential oil (EO). Fish (13.54±0.24 g) were fed with experimental diets containing 1.0 and 3.0 mL kg−1 oregano EO for 60 days. At the end of the experiment, no significant difference was found among the growth performances of fish fed with oregano EO supplemented diets (p>0.05). However, dietary administration of 3.0 mL kg−1 oregano EO had significantly increased survival rates of common carp post-challenged with A. hydrophila (p < 0.05). In addition, goblet cells number and villi length in the intestine were increased in fish fed with oregano EO diets (p < 0.001). Also, no pathological findings were observed in hepatopancreas, gonads and intestines in fish fed with oregano EO. Fish fed with a diet containing 3.0 mL kg−1 oregano EO showed higher catalase activity (CAT) than the other experimental groups (p < 0.05). Superoxide dismutase (SOD), melondialdehyde (MDA), total protein, albumin, AST, ALT and ALP levels were similar in oregano EO supplemented groups compared to the control (p > 0.05). Number of mature oocytes in female ovaries caused a slight increase in fish fed with oregano EO. Adding oregano EO to common carp diet showed improved intestinal histomorphology and increased the survival against the A. hydrophila. Therefore, O. minutiflorum EO can be used as a health promoter for carp.

Vertical distribution of Lake Superior cisco (Coregonus artedi) spawning aggregations and implications for population monitoring

Cisco (Coregonus artedi) support an evolving commercial roe fishery in Wisconsin waters of Lake Superior. To monitor trends in spawning cisco abundance, fishery managers recently began estimating adult biomass and exploitation using fall hydroacoustic surveys, which were combined with gill net surveys to inform apportionments of acoustic data. The gill net survey design consisted of paired top-suspended and bottom-set gill nets, but only the sex ratios from top nets are currently used with the hydroacoustic surveys due to an assumption that cisco in Lake Superior are pelagic spawners. However, the vertical sex distribution of cisco during spawning aggregations has been described as dynamic, with males becoming more bottom-oriented throughout the spawning season. We used multilevel aggregated binomial regressions to: 1) determine if there is bias between top and bottom gill net catches of cisco for either sex and if it changes throughout the spawning season, 2) evaluate how the vertical distribution of males and females may create bias in sex ratios used to estimate exploitation, and 3) explore the effect that maturity (i.e., gonadal development) has on vertical distribution during spawning aggregations. We identified sex-specific bias in vertical catch location that has the potential to bias estimates of sex ratio, and the source of this bias may be attributable to maturity driven changes in behavior. These findings highlight a need for caution when relying on gill nets to apportion cisco sex ratios during spawning aggregations and provide support for a non-pelagic alternative hypothesis of spawning behavior.

Effect of stocking density on gonadal development, pigmentation and survival of Carassius carassius (Crucian carp) in a biofloc system

The present study was carried out to investigate the optimum stocking density for gonadal development, pigmentation, and survival of Carassius carassius stocked at varying stocking densities under a biofloc-based system. C. carassius (25 ± 0.15 g) were randomly distributed in sixteen tanks, each with 250 L water at the stocking densities viz. 1 kg/m3, 2 kg/m3, 3 kg/m3, 4 kg/m3 (10, 20, 30 and 40 fish/250 L). The carbon‑nitrogen ratio of 15:1 was maintained using wheat flour as a carbon source. The best gonad performance in terms of absolute fecundity (4449.98 ± 115.636), relative fecundity (114.67 ± 2.770), GSI (5.62 ± 0.018 and 2.93 ± 0.014 for females & males respectively), and advanced maturation stages (vitellogenic oocytes and seminiferous tubules with spermatozoa) was observed in the density treatment having 20 fish/250 L. The skin carotenoid content showed an increasing trend with maximum content (8.11 ± 0.018 μg/g)) recorded for the fish stocked at 20/250 L. The scales of the fish from the same treatment presented a higher concentration of yellow orange pigments giving an overall golden hue to the scales while as the density and dispersion of melanophores increased with an increase in stocking density giving an overall darker coloration to the fish, indicating a stressful condition at higher stocking density. The survival rate of fish showed no significant difference (p≥0.05) between the various density groups. The results of this experiment elucidate that Carassius carassius could be cultured with better gonad performance, increased carotenoid content, and high survival at a stocking density of 2 kg/m3 in a biofloc system.

Elevated temperature impairs gonadal development by suppressing the expression of the genes for kisspeptin, GnRH1 and GTH subunits in Nile tilapia Oreochromis niloticus

Temperature is a preeminent factor in the regulation of fish reproduction and hinders gonadal development beyond a specific threshold. To comprehend the molecular mechanism responsible for reproductive suppression at different temperature, expression of the genes encoding kisspeptin (kiss2), gonadotropin-releasing hormone (gnrh1) and their receptors (gpr54, gnrh1r) in the brain, and the gonadotropin (GTH) subunits (fshb and lhb) in the pituitary were studied in juvenile Nile tilapia (Oreochromis niloticus) along with gonadal histology. Fish were acclimatized to three distinct temperatures, including 31 °C, 34 °C and 37 °C for 14 days. The mRNA levels of kiss2, gpr54, gnrh1, and gnrh1r were significantly decreased at 37 °C compared to 31 °C and 34 °C in the both sexes. In parallel, the expression level of fshb in the both sexes and lhb in the female were significantly lower at 37 °C in the pituitary. Histologically, the gonads of both sexes had normal growth of gametes at control temperature (31 °C), whereas the spermatogenesis and oocyte maturation were slowed down and atretic oocytes were found in the ovary at 37 °C acclimation temperature. Taken together, the results imply that elevated temperature beyond the specific threshold may have a negative impact on reproduction by suppressing the gene expressions of kisspeptin/GnRH1/GTH system and eventually restrains normal growth and maturation of gametes in the both sexes of Nile tilapia.

Estrogen receptor knockdown suggests its role in gonadal development regulation in Manila clam Ruditapes philippinarum

The estrogen receptor (ER), a ligand-dependent transcription factor, is critical for vertebrate reproduction. However, its role in bivalves is not well understood, with ongoing debates regarding its function in regulating reproduction similarly to vertebrates. To investigate ER's function, we conducted a 21-day RNA interference experiment focusing on its role in gonadal development in bivalves. Histological analyses revealed that ER inhibition significantly suppressed ovarian development in females and, conversely, promoted gonadal development in males. Additionally, levels of 17β-estrogen (E2) were markedly reduced in the gonads of both sexes following ER suppression. Transcriptomic analysis from RNA-seq of testes and ovaries after ER interference showed changes in the expression of key genes such as Vtg, CYP17, 3β-HSD, and 17β-HSD. These genes are involved in the estrogen signaling pathway and steroid hormone biosynthesis. Furthermore, ER suppression significantly affected the expression of genes linked to gametogenesis and the reproductive cycle. Our findings highlight ER's crucial, yet complex and sex-specific roles in gonadal development in bivalves, emphasizing the need for further detailed studies.

46,ΧΥ DSD in an adolescent with a novel de novo variant of the NR5A1 gene - case report and literature review.

In addition to chromosomal abnormalities, several genes have been implicated as causes of disorders of sex development (DSD). The NR5A1 gene expresses SF1, a transcription factor that plays a role in steroidogenesis by controlling multiple stages of adrenal and gonadal development, its mutations having been reported in cases of DSD. A 15-year-old teenager was admitted to the Children's ICU of a tertiary center due to acute encephalitis. On physical examination, labia majora and minora, open vaginal opening, and a 4.8cm phallus (stretched length) in the anatomical position of the clitoris were identified. The patient also presented with hirsutism, breast development was Tanner stage I, and pubic hair was Tanner V. Medical history revealed primary amenorrhea. Imaging studies revealed oval formations primarily compatible with testicular parenchyma in the anatomical location of the inguinal ducts. The karyotype identified a 46,XY individual, while whole exome sequencing (WES) revealed the presence of a heterozygous pathogenic splice site variant of the NR5A1 gene (NM_004959.5), c.990G > C, p.Glu330Asp, which, on further genetic testing of the parents, was proven to be de novo. According to psychiatric assessment, the patient self-identifies as a female. Laparoscopic exploration showed no residual Mullerian ducts or the presence of testicular tissue. A gonadectomy was performed and hormone replacement therapy with estrogens was initiated. We describe a rare case of 46,XY DSD in an phenotypically female adolescent carrying the novel de novo p.Glu330Asp variant of the NR5A1 gene. We also highlight the frequent delay in diagnosis of ambiguous external genitalia.

Effect of tannic acid on adiponectin and gonads in male Brandt’s voles (Lasiopodomys brandtii)

Adiponectin regulates steroid production and influences gonadal development. This study examined the effects of tannic acid (TA) on the adiponectin levels and gonads of male Brandt’s voles. Male Brandt’s voles aged 90 d were randomly separated into three groups: a control group (provided distilled water), a group given 600 mg∙kg-1 TA, and a group that received 1200 mg∙kg-1 TA (continuous gavage for 18 d). In this study, we examined the effects of TA on the adiponectin, antioxidant, and inflammatory levels in the testes. Furthermore, we examined the expression of important regulatory elements that influence adiponectin expression and glucose utilisation. In addition, the body weight, reproductive organ weight, and testicular shape were assessed. Our study observed that TA treatment increased serum adiponectin levels, DsbA-L and Ero1-Lα transcription levels, and AdipoR1, AMPK, GLUT1, and MCT4 expression levels in testicular tissue. TA enhanced pyruvate and lactic acid levels in the testicular tissue, boosted catalase activity, and reduced MDA concentrations. TA reduced the release of inflammatory factors in the testicular tissues of male Brandt’s voles. TA increased the inner diameter of the seminiferous tubules. In conclusion, TA appears to stimulate adiponectin secretion and gonadal growth in male Brandt’s voles while acting as an antioxidant and anti-inflammatory agent.

Comparative Transcriptome Analysis of the Hypothalamic-Pituitary-Gonadal Axis of Jinhu Grouper (Epinephelus fuscoguttatus ♀ × Epinephelus tukula ♂) and Tiger Grouper (Epinephelus fuscoguttatus).

Jinhu groupers, the hybrid offspring of tiger groupers (Epinephelus fuscoguttatus) and potato groupers (Epinephelus tukula), have excellent heterosis in fast growth and strong stress resistance. However, compared with the maternal tiger grouper, Jinhu groupers show delayed gonadal development. To explore the interspecific difference in gonadal development, we compared the transcriptomes of brain, pituitary, and gonadal tissues between Jinhu groupers and tiger groupers at 24-months old. In total, 3034 differentially expressed genes (DEGs) were obtained. KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analyses showed that the osteoclast differentiation, oocyte meiosis, and ovarian steroidogenesis may be involved in the difference in gonadal development. Trend analysis showed that the DEGs were mainly related to signal transduction and cell growth and death. Additionally, differences in expression levels of nr4a1, pgr, dmrta2, tbx19, and cyp19a1 may be related to gonadal retardation in Jinhu groupers. A weighted gene co-expression network analysis revealed three modules (i.e., saddlebrown, paleturquoise, and greenyellow) that were significantly related to gonadal development in the brain, pituitary, and gonadal tissues, respectively, of Jinhu groupers and tiger groupers. Network diagrams of the target modules were constructed and the respective hub genes were determined (i.e., cdh6, col18a1, and hat1). This study provides additional insight into the molecular mechanism underlying ovarian stunting in grouper hybrids.

Histological study of the sex ratio and reproductive cycle of the mangrove oyster Crassostrea tulipa (Lamarck, 1819) in the Saloum Delta (Senegal)

The mangrove oyster Crassostrea tulipa has considerable socio-economic value in Senegal, as in many other West African countries. To better understand its biology, the objective of this study was to determine the sex ratio and the evolution of gonadal development stages of oyster populations in the Saloum Delta. To this end, a monthly sampling of 30 oysters between 34.19 mm and 96.68 mm height was carried out between January 2021 and January 2022. The part of the flesh that encloses the gonads was removed and fixed using Davidson's solution. After dehydration, paraffining and inclusion of the materials, 7 μm thick sections were made using a microtome. These sections were stained with Haris’s hematoxylin and eosin and the slides were observed under an optical microscope (Olympus BX41 microscope).The results showed a predominance of females over males, with a sex ratio of 1 in 2.85. The results also revealed that reproduction was continuous over the year and that spawning was asynchronous: Individuals at the spawning stage were more frequent in the warm season. These results will contribute to a better management of natural stocks and to improve oyster farming.

Diaph1 knockout inhibits mouse primordial germ cell proliferation and affects gonadal development

BackgroundExploring the molecular mechanisms of primordial germ cell (PGC) migration and the involvement of gonadal somatic cells in gonad development is valuable for comprehending the origins and potential treatments of reproductive-related diseases.MethodsDiaphanous related formin 1 (Diaph1, also known as mDia1) was screened by analyzing publicly available datasets (ATAC-seq, DNase-seq, and RNA-seq). Subsequently, the CRISPR-Cas9 technology was used to construct Diaph1 knockout mice to investigate the role of Diaph1 in gonad development.ResultsBased on data from public databases, a differentially expressed gene Diaph1, was identified in the migration of mouse PGC. Additionally, the number of PGCs was significantly reduced in Diaph1 knockout mice compared to wild type mice, and the expression levels of genes related to proliferation (Dicer1, Mcm9), adhesion (E-cadherin, Cdh1), and migration (Cxcr4, Hmgcr, Dazl) were significantly decreased. Diaph1 knockout also inhibited Leydig cell proliferation and induced apoptosis in the testis, as well as granulosa cell apoptosis in the ovary. Moreover, the sperm count in the epididymal region and the count of ovarian follicles were significantly reduced in Diaph1 knockout mice, resulting in decreased fertility, concomitant with lowered levels of serum testosterone and estradiol. Further research found that in Diaph1 knockout mice, the key enzymes involved in testosterone synthesis (CYP11A1, 3β-HSD) were decreased in Leydig cells, and the estradiol-associated factor (FSH receptor, AMH) in granulosa cells were also downregulated.ConclusionsOverall, our findings indicate that the knockout of Diaph1 can disrupt the expression of factors that regulate sex hormone production, leading to impaired secretion of sex hormones, ultimately resulting in damage to reproductive function. These results provide a new perspective on the molecular mechanisms underlying PGC migration and gonadal development, and offer valuable insights for further research on the causes, diagnosis, and treatment of related diseases.

Genome-wide analysis of the cytochrome P450 gene family in Pacific oyster Crassostrea gigas and their expression profiles during gonad development

The cytochrome P450 (CYP) gene superfamily plays a significant role in various physiological processes, producing different compounds such as hormones, fatty acids, and biomolecules. However, little information is known their roles during gonad development in Pacific oyster (Crassostrea gigas). In this study, total of 116 CgCYP (Crassostrea gigas cytochrome P450) genes were identified and their expression pattern was analyzed for the first time. The relative molecular weights of these CgCYP genes ranged from 63.52 to 113.41 kDa, and the length of encoded amino acids ranged from 103 to 993. And total 26 cis-acting elements of these CgCYP genes were identified. GO and KEGG enrichment analysis showed some CgCYP genes are essential for the metabolism of male and female sex hormones. Additionally, expression anslysis showed 69 CgCYP genes were over-expressed in early gonad development and triploid infertile individuals. More importantly, expression levels of CgCYP1, CgCYP15, CgCYP34, CgCYP46, CgCYP69, CgCYP87, CgCYP88, and CgCYP103, were found to be significantly higher in female gonad, suggesting their important roles in female gonad development. The results of this study will provide a better understanding of the CgCYP genes in the gonad development of Pacific oyster.

Differential expression and genetic polymorphism of DMRT1 and FOXL2 genes in the gonads of Kadaknath chicken

In chicken, the left ovary is functional and the right ovary becomes rudimentary in the later stage of the embryonic development. The expression and genetic polymorphism of the DMRT1 and FOXL2 genes are assessed in order to understand the distinct developing process of gonads in male and female embryonic gonads. In the current study, 19th day Kadaknath chicken gonadal tissue samples were collected from the embryos and RT-PCR analysis and DNA sequencing was done. According to the expression studies, the left ovaries relative expression of FOXL2 was 2.14 and 12.65 factor greater than that of the right ovaries and testes, while the right testis relative expression of DMRT1 was 3.78 and 3.83 fold higher than that of the left and right ovaries. DNA sequence analysis in the left ovary identified a nonsynonymous alteration (c.289C&gt;G) involving histidine to aspartic acid at the 289th position in the FOXL2 coding region. The 51st position of exon 6 of DMRT1 has a G→A transition SNP that is not part of the coding sequence (CDS). Males showed higher levels of the DMRT1 gene than females, while females expressed higher levels of FOXL2. It was found that the DMRT1 and FOXL2 genes are polymorphic. The genetic variability in the gonads and the differences in DMRT1 and FOXL2 gene expression allow learning more about the critical mechanisms underlying chicken gonadal development.

Cloning and expression patterns of espl1 gene in loach (Misgurnus anguillicaudatus) during gonad development

espl1 (extra spindle pole bodies like 1), a cysteine endopeptidase, is a mitotic key player in chromosomal segregation and centriole duplication during mitosis and meiosis. Considering the espl1 gene has not been reported in aquatic organisms, we reported the isolation and expression of the espl1 gene from loach. In this study, the full-length cDNA of espl1 was cloned for the first time in loach. In loach, the full-length cDNA of espl1 consisted of 6948 bp, the open reading frame (ORF) is 6240 bp, and the espl1 gene encodes 2139 amino acids. Moreover, the deduced amino acid sequences of espl1 in loach shared the highest identity with those of Cyprinus carpio (78.39%) and Sinocyclocheilus anshuiensis (78.27%), and the sequence homology among the various separases is confined to the C-terminal region. Furthermore, tissue-specific checking results indicated that the espl1 gene of the loach gene was highly expressed in the ovary and testis, especially in stage Ⅳ oocytes and stage Ⅳ testis by Real-time quantitative PCR (qPCR). Then, whole-mount in situ hybridization analyses revealed the expression of espl1 in the early development of loach. We found that the positive signal of espl1 was observed in the notochord during the early embryo development of loach. Last but not least, when treated with luteinizing hormone-releasing hormone analog (LHRH-A2), the mRNA expression of espl1 was significantly increased in the testes and ovaries. These observations suggest that the espl1 gene had a distinct and important role in the gonads of Loach. This study will be of value for further studies into the function of the espl1 gene in fish.

P-011 Maternal gestational methyl donor deficiency affects reproductive development and fertility of mice offspring

Abstract Study question Is maternal methyl donor deficiency during gestation affects offspring’s reproductive health at adulthood? Summary answer Maternal gestational methyl donor deficiency affects reproductive development and fertility of F1 offspring and also leads to increased post implantation loss What is known already Reproductive disorders and their exact mechanisms are scarce in “The developmental origins of health and disease” (DOHaD) hypothesis which well explains the metabolic complications such as obesity, type 2 diabetes and hypertension that may take root during early development. The maternal nutritional environment during early development has important implications on offspring’s health later in life including reproductive health. The gestational period is of critical importance during which major epigenetic reprogramming occurs. The maternal methyl donor deficiency during gestational period may affect this process and epigenetic signatures of developing gametes and the fertility potential Study design, size, duration Pregnant female OCT4-GFP mice, fed on control chow diet (CCD) &amp; 40% methyl-donors (Folate, Methionine &amp; Vitamin B12) deficient diet (MDD) from gestation day (GD) 5 to GD 20. The gonadal development of F1 offsprings was studied on gestation day GD 18, post-natal day (PND) 22 and PND 60. Fertility study was done by mating adult F1 male offspring with adult female mice fed on standard diet Participants/materials, setting, methods Homocysteine levels in dams (F0) at GD18 were estimated by ELISA. Testosterone levels in F1 offsprings at PND 60 were estimated by ELISA. Furthermore, Serum glucose levels in F1 offsprings were measured at PND 60 and PND 75 by glucometer. Testicular histology, quantitative histomorphometry, immunofluorescence and TUNEL assay was performed at PND 60. Main results and the role of chance Fetal weight was reduced at GD13 and GD18 but postnatal body weight at PND 22 and 60 was not significantly affected in MDD group. Teratological defects were observed in pups of 40% MDD group as compared to CDD. Testosterone levels were significantly reduced in F1 offsprings of 40% MDD group. Glucose levels were similar in both the groups at PND 60 but at PND 75 it is significantly higher in case of F1 offsprings of 40% MDD. Maternal serum homocysteine levels and global DNA methylation levels of fetal gonads were affected. Testicular histology was significantly impaired in 40% MDD group at GD18, PND22 and PND60. Quantitative histomorphometry and immunofluorescence study showed the loss of spermatogonia and spermatocytes with significant increase in germ cells sloughing and seminiferous tubules atrophy. Apoptosis is also observed in seminiferous tubules. Copulation index, sperm count and motility was significantly reduced in case of 40% MDD group at adulthood. The F1 offspring of this group were sub-fertile with significant post implantation loss. Limitations, reasons for caution Although mice share ∼90% genome with humans, they may not resemble all aspect of physiology or pathology in humans hence it could limit the findings to extrapolate to humans. Wider implications of the findings The knowledge gained from this work could be helpful in highlighting the need of gestational micronutrient interventions specially methyl donors, which could help improving maternal and child health as well as reducing the future disease burden of reproductive disorders Trial registration number not applicable