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Journal of Morphology Sep 2023Reproduction is a key step for propagation of any species. Consequently, gametogenesis is crucial, as it links one generation to the other. Oogenesis is influenced by...
Reproduction is a key step for propagation of any species. Consequently, gametogenesis is crucial, as it links one generation to the other. Oogenesis is influenced by different factors, but it is usually related to the quality and quantity of the food and the capacity of the female to convert these resources into egg production. In Demospongiae (Porifera), oocytes vary in several aspects (e.g., origin, size, and vitellogenic pathways). However, data on oocyte morphology is still fragmentary, and the ultrastructural organization of reproductive cells has been investigated only in a few species, mainly of viviparous sponges. Here, we aimed to comprehend the oogenesis of two tropical oviparous demosponges (Cinachyrella apion and Tethya maza) using light and electron microscopy. In both species, oocytes seemed to originate from archaeocytes. Oocytes of C. apion were surrounded by a collagenous matrix and nurse cells containing many lipid vesicles. The increase of biosynthetic organelles, concomitantly with the presence of yolk vesicle in the ooplasm, indicated that the vitellogenesis was carried out through the mixed pathway. The oocytes of T. maza were surrounded by a follicle cell membrane and nurse cells containing yolk vesicles. The absence of characteristic biosynthetic organelles in the egg of this species indicated that vitellogenesis occured through the heterosynthetic pathway. The oogenesis of C. apion is similar to other species of the genus, while the follicle membrane and nurse cells surrounding the oocytes of T. maza are not observed in any other species of Tethya. These accessory cells were considered to have a trophic role during the oogenesis of the studied species. Moreover, the presence of these accessory cells may have ecological significance, as they accelerate the egg's production through trophic support of the growing oocyte.
Topics: Female; Animals; Oviparity; Oogenesis; Oocytes; Ovarian Follicle; Porifera
PubMed: 37585226
DOI: 10.1002/jmor.21625 -
Cells Nov 2023(1) Fshβ and Lhβ showed stronger signals and higher transcript levels from 590 to 1050 dph than at earlier stages, implying their active involvement during primary...
Chronological Changes in Gonadotropin-Releasing Hormone 1, Gonadotropins, and Sex Steroid Hormones along the Brain-Pituitary-Gonadal Axis during Gonadal Sex Differentiation and Development in the Longtooth Grouper, .
(1) Fshβ and Lhβ showed stronger signals and higher transcript levels from 590 to 1050 dph than at earlier stages, implying their active involvement during primary oocyte development. (2) Fshβ and Lhβ at lower levels were detected during the phases of ovarian differentiation and oogonial proliferation. (3) E concentrations increased significantly at 174, 333, and 1435 dph, while T concentrations exhibited significant increases at 174 and 333 dph. These findings suggest potential correlations between serum E concentrations and the phases of oogonial proliferation and pre-vitellogenesis.
Topics: Female; Animals; Bass; Sex Differentiation; Gonadotropin-Releasing Hormone; Gonadal Steroid Hormones; Follicle Stimulating Hormone, beta Subunit; Luteinizing Hormone, beta Subunit; Brain
PubMed: 37998369
DOI: 10.3390/cells12222634 -
General and Comparative Endocrinology Feb 2024We evaluated the onset of puberty of first-generation (F1) hatchery-produced greater amberjack (Seriola dumerili) reared in sea cages for 5 years. Fish were sampled...
We evaluated the onset of puberty of first-generation (F1) hatchery-produced greater amberjack (Seriola dumerili) reared in sea cages for 5 years. Fish were sampled every year in June, at the expected peak of the spawning period in the Mediterranean Sea. No sexual dimorphism in body weight was observed in the study. The ovaries of 1 and 2-year-old (yo) females consisted of primary oocytes only, while at the age of 3-yo early vitellogenic (Vg) oocytes were also identified, but with extensive follicular atresia. At the age of 4-yo, late Vg oocytes were observed, but again extensive follicular atresia characterized the ovaries of 50 % of females. At the age of 5-yo, follicular atresia of Vg oocytes was very limited. In males, gametogenesis was evident already in 1- and 2-yo fish, and 100 % of sampled 3-yo males produced collectable viable sperm. Plasma testosterone (T), 17β-estradiol (E2), and 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P) remained similar in 3 - 5-yo females, with T and E2 levels being highest in females in advanced vitellogenesis or with significant follicular atresia, compared to immature females. In males, plasma T declined over the years, while 11-ketotestosterone (11-KT) and 17,20β-P were highest in 4 and 5-yo males, with spermatozoa motility characteristics being improved from the 4th year onwards. The administration of GnRHa implants to 5-yo fish induced only two spawns, albeit no fertilized eggs were obtained. The results indicate that hatchery-produced greater amberjack males mature well and within the same age observed in the wild, however with smaller gonad size. On the contrary, females mature later than in the wild, also with a smaller gonad size. Spawning in response to GnRHa treatment was not effective, suggesting that Mediterranean hatchery-produced broodstocks may be dysfunctional, and further research is needed to document any improvement as the fish get older, or to determine if the results may be related to the specific stock of fish.
Topics: Animals; Female; Male; Sexual Maturation; Follicular Atresia; Semen; Perciformes; Ovary; Fishes
PubMed: 38008343
DOI: 10.1016/j.ygcen.2023.114414 -
Nutrients Mar 2024Caffeine (1,3,7-trimethylxanthine) is a widely consumed bioactive substance worldwide. Our recent study showed that a reduction in both reproduction and yolk protein...
Caffeine (1,3,7-trimethylxanthine) is a widely consumed bioactive substance worldwide. Our recent study showed that a reduction in both reproduction and yolk protein production (vitellogenesis) caused by caffeine intake were improved by vitamin B12 supplementation, which is an essential co-factor in methionine metabolism. In the current study, we investigated the role of methionine in the reproduction of caffeine-ingested animals (CIAs). We assessed the effect of methionine metabolism on CIAs and found that caffeine intake decreased both methionine levels and essential enzymes related to the methionine cycle. Furthermore, we found that the caffeine-induced impairment of methionine metabolism decreased vitellogenesis and increased germ cell apoptosis in an LIN-35/RB-dependent manner. Interestingly, the increased germ cell apoptosis was restored to normal levels by methionine supplementation in CIAs. These results indicate that methionine supplementation plays a beneficial role in germ cell health and offspring development by regulating vitellogenesis.
Topics: Animals; Methionine; Caenorhabditis elegans; Caffeine; Apoptosis; Germ Cells; Racemethionine; Dietary Supplements
PubMed: 38542805
DOI: 10.3390/nu16060894 -
International Journal of Molecular... Jan 2024Vitellogenin () is a precursor of yolk proteins in egg-laying vertebrates and invertebrates and plays an important role in vitellogenesis and embryonic development....
Vitellogenin () is a precursor of yolk proteins in egg-laying vertebrates and invertebrates and plays an important role in vitellogenesis and embryonic development. However, the family remains poorly characterized in , a major commercial mariculture species found along the coasts of the Yellow and Bohai Seas. In this study, 10 genes from the genomes of were identified and characterized. Phylogenetic analyses showed that the genes in crustaceans could be classified into four groups: Astacidea, Brachyra, Penaeidae, and Palaemonidae. genes were unevenly distributed on the chromosomes of , and a molecular evolutionary analysis showed that the genes were primarily constrained by purifying selection during evolution. All putative proteins were characterized by the presence of three conserved functional domains: a lipoprotein N-terminal domain (LPD_N), a domain of unknown function (DUF1943), and a von Willebrand factor type D domain (vWD). All genes exhibited higher expression in the female hepatopancreas than in other tissues, and gene expression during ovarian development suggested that the hepatopancreas is the main synthesis site in . , , and play major roles in exogenous vitellogenesis, and also plays a major role in endogenous vitellogenesis. Bilateral ablation of the eyestalk significantly upregulates mRNA expression in the female hepatopancreas, indicating that the X-organ/sinus gland complex plays an important role in ovarian development, mostly by inducing synthesis. These results could improve our understanding of the function of multiple genes in crustaceans and aid future studies on the function of genes during ovarian development in .
Topics: Animals; Female; Vitellogenins; Palaemonidae; Phylogeny; Embryonic Development; Evolution, Molecular
PubMed: 38256163
DOI: 10.3390/ijms25021089 -
Zoo Biology 2023The golden lancehead (Bothrops insularis) is a critically endangered snake endemic to Queimada Grande Island, southeastern Brazil. Captive breeding programs are vital...
The golden lancehead (Bothrops insularis) is a critically endangered snake endemic to Queimada Grande Island, southeastern Brazil. Captive breeding programs are vital for the conservation of this species. This study evaluates the gestation of two females golden lanceheads using radiography and ultrasonography. The first female was collected on the island while reproductively active (late vitellogenesis or early pregnancy) and kept in captivity. This female gave birth to five neonates after an 8-month gestation period, which is longer than estimates based on specimens preserved in museums. The second female copulated in captivity in July and probably ovulated in October. In this case, no embryonic development was detected, and the female deposited 14 undeveloped eggs approximately 6 months after ovulation.
Topics: Female; Animals; Pregnancy; Bothrops; Animals, Zoo; Brazil
PubMed: 36959717
DOI: 10.1002/zoo.21764 -
Comparative Biochemistry and... Dec 2023Blue mussels (Mytilus sp.) are an economically important species for European aquaculture. Their importance as a food source is expected to increase in the coming...
Blue mussels (Mytilus sp.) are an economically important species for European aquaculture. Their importance as a food source is expected to increase in the coming net-zero society due to their low environmental footprint; however, their production is affected by anthropogenic stressors and climate change. During reproduction, lipids are key molecules for mussels as they are the main source of energy on which newly hatched embryos depend in the first days of their development. In this work, blue mussels of different origins are analysed, focusing on the differences in lipid composition between the ovary (BMO) and the testis (BMT). The lipidome of blue mussel gonads (BMG) is studied here by combining traditional lipid profiling methods, such as fatty acid and lipid class analysis, with untargeted liquid chromatography-mass spectrometry (LC-MS) lipidomics. The approach used here enabled the identification of 770 lipid molecules from 23 different lipid classes in BMG. BMT, which consists of billions of spermatocytes, had greater amounts of cell membrane and membrane lipid components such as FA18:0, C20 polyunsaturated fatty acids (PUFA), free sterols (ST), ceramide phosphoethanolamines (CerPE), ceramide aminoethylphosphonates (CAEP), cardiolipins (CL), glycerophosphocholines (PC), glycerophosphoethanolamines (PE) and glycerophosphoserines (PS). In BMO, saturated fatty acids (FA14:0 and FA16:0), monounsaturated fatty acids (MUFA) and other storage components such as C18-PUFA accumulated in triradylglycerolipids (TG) and alkyldiacylglycerols (neutral plasmalogens, TG O-), which, together with terpenes, wax esters and cholesterol esters, make up most of oocytes yolk reserves. BMO also had higher levels of ceramides (Cer) and generally alkyl/alkenyl glycerophospholipids (mainly plasmanyl/plasmenyl PC), suggesting a role for these lipids in vitellogenesis. Non-methylene interrupted dienoic fatty acids (NMID FA), typically found in plasmalogens, were the only membrane-forming PUFA predominantly detected in BMO. The results of this study are of great importance for clarifying the lipid composition of BMG and provide an important basis for future studies on the reproductive physiology of these organisms.
Topics: Male; Female; Animals; Mytilus edulis; Mytilus; Lipidomics; Plasmalogens; Sex Characteristics; Fatty Acids; Fatty Acids, Unsaturated; Gonads; Ceramides
PubMed: 37913700
DOI: 10.1016/j.cbd.2023.101150 -
BMC Zoology Jul 2023The precise mechanisms of hormone action responsible for the full course of events modulating folliculogenesis in crocodilian have not been determined, although...
BACKGROUND
The precise mechanisms of hormone action responsible for the full course of events modulating folliculogenesis in crocodilian have not been determined, although histological features have been identified.
RESULTS
The Alligator sinensis ovarian morphological characteristics observed at 1, 15, 30, 60, 90, and 300 days post hatching(dph) revealed that the dynamic changes in germ cells varied in different meiotic and developmental stages, confirming that the processes of folliculogenesis were protracted and asynchronous. The presence of endogenous follicle-stimulating hormone(FSH) mRNA and protein expression within the cerebrum at 1 dph, in parallel with the increase in germ cells within the germ cell nests(Nest) from 1 dph to 15 dph, suggested that endocrine regulation of the pituitary-gonad axis is an early event in oogonia division. Furthermore, the endogenous expression of FSH showed a trend of negative feedback augmentation accompanied by the exhaustion of maternal yolk E observed at 15 dph. Such significant elevation of endogenous FSH levels was observed to be related to pivotal events in the transition from mitosis to meiosis, as reflected by the proportion of oogonia during premeiosis interphase, with endogenous FSH levels reaching a peak at the earliest time step of 1 dph. In addition, the simultaneous upregulation of premeiotic marker STRA8 mRNA expression and the increase in endogenous FSH further verified the above speculation. The strongly FSHr-positive label in the oocytes within Pre-previtellogenic follicles was synchronized with the significant elevation of ovarian cAMP detected at 300 dph, which suggested that diplotene arrest maintenance during early vitellogenesis might be FSH dependent. In addition, preferential selection in asynchronous meiotic initiation has been supposed to act on somatic supportive cells and not directly on germ cells via regulation of FSH that in turn affects downstream estrogen levels. This suggestion was verified by the reciprocal stimulating effect of FSH and E on the accelerated meiotic marker SYCP3 and by the inhibited cell apoptosis demonstrated in ovarian cell culture in vitro.
CONCLUSION
The corresponding results contribute an expansion of the understanding of physiological processes and shed some light on the specific factors responsible for gonadotropin function in the early folliculogenesis of crocodilians.
PubMed: 37403129
DOI: 10.1186/s40850-023-00170-z -
International Journal of Molecular... Dec 2023Methyl farnesoate (MF), a crucial sesquiterpenoid hormone, plays a pivotal role in the reproduction of female crustaceans, particularly in the vitellogenesis process....
Methyl farnesoate (MF), a crucial sesquiterpenoid hormone, plays a pivotal role in the reproduction of female crustaceans, particularly in the vitellogenesis process. Despite extensive research on its functions, the molecular mechanisms that regulate MF levels during the vitellogenic phase remain largely elusive. This study investigates the roles of microRNAs (miRNAs), significant post-transcriptional regulators of gene expression, in controlling MF levels in the swimming crab . Through bioinformatic analysis, four miRNAs were identified as potential regulators targeting two genes encoding Carboxylesterases (CXEs), which are key enzymes in MF degradation. Dual luciferase reporter assays revealed that and suppress and expression by directly binding to their 3' UTRs. In vivo overexpression of and significantly diminished and levels, consequently elevating hemolymph MF and enhancing expression. Spatiotemporal expression profile analysis showed that these two miRNAs and their targets exhibited generally opposite patterns during ovarian development. These findings demonstrate that and collaboratively modulate MF levels by targeting , thus influencing vitellogenesis in . Additionally, we found that the expression of and were suppressed by MF, constituting a regulatory loop for the regulation of MF levels. The findings contribute novel insights into miRNA-mediated ovarian development regulation in crustaceans and offer valuable information for developing innovative reproduction manipulation techniques for .
Topics: Animals; Female; 3' Untranslated Regions; Brachyura; Carboxylic Ester Hydrolases; Fatty Acids, Unsaturated; MicroRNAs; Vitellogenesis
PubMed: 38203450
DOI: 10.3390/ijms25010279 -
IScience Feb 2024Energy reserves, primarily stored in the insect's fat body, are essential for physiological processes such as reproduction and cocoon formation. However, whether these...
Energy reserves, primarily stored in the insect's fat body, are essential for physiological processes such as reproduction and cocoon formation. However, whether these processes are mutually constraining is unknown. Here, we showed that cocoon-free silkworms accumulate amino acid constituents of silk proteins in the hemolymph and maintain lipid and sugar reserves in the pupal fat body by repressing the expression of sericin and fibroin genes in the middle and posterior silk glands, respectively, via butterfly pierisin-1A catalytic domain expression. This, in turn, upregulates insulin/insulin-like signaling and target of rapamycin (IIS/TOR) signaling, which enhances vitellogenesis and accelerates ovarian development, thus contributing to increased fecundity. The impacts of semi-starvation on fecundity and egg hatchability were also less pronounced in cocoon-free silkworms compared with wildtype silkworms. These data uncover the resource allocation trade-off between cocoon formation and fecundity and demonstrate that nutritional signaling plays a role in regulating silkworm reproduction.
PubMed: 38303707
DOI: 10.1016/j.isci.2024.108853