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PloS One 2023Ecdysteroids control ovary growth and egg production through a complex gene hierarchy. In the female Rhodnius prolixus, a blood-gorging triatomine and the vector of...
Ecdysteroids control ovary growth and egg production through a complex gene hierarchy. In the female Rhodnius prolixus, a blood-gorging triatomine and the vector of Chagas disease, we have identified the ecdysone response genes in the ovary using transcriptomic data. We then quantified the expression of the ecdysone response gene transcripts (E75, E74, BR-C, HR3, HR4, and FTZ-F1) in several tissues, including the ovary, following a blood meal. These results confirm the presence of these transcripts in several tissues in R. prolixus and show that the ecdysone response genes in the ovary are mostly upregulated during the first three days post blood meal (PBM). Knockdown of E75, E74, or FTZ-F1 transcripts using RNA interference (RNAi) was used to understand the role of the ecdysone response genes in vitellogenesis and egg production. Knockdown significantly decreases the expression of the transcripts for the ecdysone receptor and Halloween genes in the fat body and the ovaries and reduces the titer of ecdysteroid in the hemolymph. Knockdown of each of these transcription factors typically alters the expression of the other transcription factors. Knockdown also significantly decreases the expression of vitellogenin transcripts, Vg1 and Vg2, in the fat body and ovaries and reduces the number of eggs produced and laid. Some of the laid eggs have an irregular shape and smaller volume, and their hatching rate is decreased. Knockdown also influences the expression of the chorion gene transcripts Rp30 and Rp45. The overall effect of knockdown is a decrease in number of eggs produced and a severe reduction in number of eggs laid and their hatching rate. Clearly, ecdysteroids and ecdysone response genes play a significant role in reproduction in R. prolixus.
Topics: Animals; Female; Ecdysone; Ecdysteroids; Rhodnius; Ovary; Vitellogenesis
PubMed: 36940230
DOI: 10.1371/journal.pone.0283286 -
Animals : An Open Access Journal From... Jan 2023The meagre (Asso, 1801) is a promising aquaculture species that shows reproductive dysfunctions when reared in tanks. The aim of this study was to assess the capacity...
The meagre (Asso, 1801) is a promising aquaculture species that shows reproductive dysfunctions when reared in tanks. The aim of this study was to assess the capacity of meagre, reared in cages under routine farming conditions, to mature gonads and reproduce spontaneously. Meagre adults, reared in a fish farm located in the Gulf of Taranto (Italy), were sampled from March to July 2021. The gonadosomatic index and sex steroid plasma concentrations increased from March-April to June, and then decreased in July. In March-April, most of the females showed perinucleolar or cortical alveoli oocytes as the most advanced stages in the ovaries, and most of the males had testes at early spermatogenesis stage. In June, most of the sampled females had oocytes at late vitellogenesis or early post-vitellogenesis stages, and males had seminiferous tubules filled with spermatozoa. In July, most of the females had signs of previous spawning, and males showed scarce amounts of luminal spermatozoa. The present study demonstrated the capacity of meagre, reared in sea cages under commercial conditions, to carry out gametogenesis and spontaneously release gametes. Meagre reproduction, under routine farming conditions, may represent an opportunity for the expansion of meagre aquaculture production.
PubMed: 36670763
DOI: 10.3390/ani13020223 -
Cells Dec 2022Several endocrine signals mediate mosquito egg development, including 20-hydroxyecdysone (20E). This study reports on prostaglandin E (PGE) as an additional, but core,...
Several endocrine signals mediate mosquito egg development, including 20-hydroxyecdysone (20E). This study reports on prostaglandin E (PGE) as an additional, but core, mediator of oogenesis in a human disease-vectoring mosquito, . Injection of aspirin (an inhibitor of cyclooxygenase (COX)) after blood-feeding (BF) inhibited oogenesis by preventing nurse cell dumping into a growing oocyte. The inhibitory effect was rescued by PGE addition. PGE was found to be rich in nurse cells and follicular epithelium after BF. RNA interference (RNAi) treatments of PG biosynthetic genes, including PLA and two COX-like peroxidases, prevented egg development. Interestingly, 20E treatment significantly increased the expressions of PG biosynthetic genes, while the RNAi of (which is a 20E biosynthetic gene) expression prevented inducible expressions after BF. Furthermore, RNAi treatments of PGE receptor genes suppressed egg production, even under PGE. These results suggest that a signaling pathway of BF-20E-PGE is required for early vitellogenesis in the mosquito.
Topics: Animals; Aedes; Aspirin; Cyclooxygenase 2; Dinoprostone; Oocytes; Oogenesis
PubMed: 36552860
DOI: 10.3390/cells11244092 -
Biology Letters Dec 2022Optimistic and pessimistic cognitive biases have been described in many animals and are related to the perceived valence of the environment. We, therefore, hypothesize...
Optimistic and pessimistic cognitive biases have been described in many animals and are related to the perceived valence of the environment. We, therefore, hypothesize that such cognitive bias can be adaptive depending on environmental conditions. In reward-rich environments, an optimistic bias would be favoured, whereas in harsh environments, a pessimistic one would thrive. Here, we empirically investigated the potential adaptive value of such bias using zebrafish as a model. We first phenotyped female zebrafish in an optimistic/pessimistic axis using a previously validated judgement bias assay. Optimistic and pessimistic females were then exposed to an unpredictable chronic stress protocol for 17 days, after which fish were euthanized and the sectional area of the different ovarian structures was quantified in both undisturbed and stressed groups. Our results show that zebrafish ovarian development responded to chronic stress, and that judgement bias impacted the relative area of the vitellogenic developmental stage, with pessimists showing higher vitellogenic areas as compared with optimists. These results suggest that pessimism maximizes reproductive investment, through increased vitellogenesis, indicating a relationship between cognitive bias and life-history organismal decisions.
Topics: Animals; Female; Zebrafish; Pessimism; Judgment; Cognition; Bias
PubMed: 36541092
DOI: 10.1098/rsbl.2022.0232 -
Marine Environmental Research Jan 2023Follicular atresia is an energy-saving oocyte resorption process that can allow the survival of female fish when environmental conditions are unfavourable and at the...
Follicular atresia is an energy-saving oocyte resorption process that can allow the survival of female fish when environmental conditions are unfavourable and at the expense of fecundity. This study investigated the transcription levels of apoptosis and autophagy-related genes during atresia in the European hake that can show episodes of increased follicular atresia throughout the reproductive cycle. 169 female individuals were collected from the Bay of Biscay, and the ovaries were analysed using histological and molecular methods. Different levels of atresia were histologically detected in 73.7% of the ovaries analysed and the TUNEL assay identified apoptotic nuclei in follicles from both previtellogenic and vitellogenic stages. Transcripts of beclin-1 and ptenb were up-regulated in the ovaries containing atretic follicles, whereas p53, caspase-3, cathepsin D and dapk1 were up-regulated only in ovaries presenting vitellogenic atretic follicles. Our results indicate different implications of apoptotic vs autophagic processes leading to atresia during oocyte development, vitellogenesis being the moment of maximal apoptotic and autophagic activity in atretic hakes. The analysed genes could provide early warning biomarkers to identify follicular atresia in fish and evaluate fecundity in fish stocks.
Topics: Animals; Female; Ovary; Gadiformes; Follicular Atresia; Apoptosis; Fishes; Perciformes; Transcription, Genetic; Autophagy
PubMed: 36521304
DOI: 10.1016/j.marenvres.2022.105846 -
Anais Da Academia Brasileira de Ciencias 2022Reproductive biology is fundamental to understanding the ecology and evolution of lizards which, in turn, is essential for the definition of the species´ conservation...
Reproductive biology is fundamental to understanding the ecology and evolution of lizards which, in turn, is essential for the definition of the species´ conservation status. We studied life-history traits related to the reproduction of the Phymaturus extrilidus lizard, including the male and female reproductive cycles, litter size, mean annual reproductive output, reproductive effort, sexual maturity size and sexual dimorphism, body condition, and fat body cycles. We found sexual dimorphism in size and shape, supporting the hypotheses of sexual and fecundity selection. Females exhibited biennial reproductive cycles synchronous with the annual prenuptial male cycle, adjusted for the maturation of the vitellogenic follicles of females. Females of P. extrilidus have the highest mean annual reproductive output (MARO=1.14) recorded in Phymaturus, and this is accompanied by the highest reproductive effort (C=0.28, C energetic =0.31). Births occur from late summer to early autumn. The female reproductive cycle, strictly biennial, like all species of the P. palluma group, and the vitellogenesis in particular, appear to be limited by body condition and the amount of fat body stored. This study presents the fundamental reproductive traits of P. extrilidus that can provide valuable information to be used in the evaluation of the conservation status of this species.
Topics: Animals; Female; Male; Lizards; Sex Characteristics; Altitude; Argentina; Reproduction; Biology
PubMed: 36515324
DOI: 10.1590/0001-3765202220210179 -
PeerJ 2022Sexual growth dimorphism is a common phenomenon in teleost fish and has led to many reproductive strategies. Growth- and sex-related gene research in teleost fish would...
Sexual growth dimorphism is a common phenomenon in teleost fish and has led to many reproductive strategies. Growth- and sex-related gene research in teleost fish would broaden our understanding of the process. In this study, transcriptome sequencing of shortfin scad was performed for the first time, and a high-quality reference transcriptome was constructed. After identification and assembly, a total of 58,475 nonredundant unigenes were obtained with an N50 length of 2,266 bp, and 28,174 unigenes were successfully annotated with multiple public databases. BUSCO analysis determined a level of 92.9% completeness for the assembled transcriptome. Gene expression analysis revealed 2,345 differentially expressed genes (DEGs) in the female and male , 1,150 of which were female-biased DEGs, and 1,195 unigenes were male-biased DEGs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that the DEGs were mainly involved in biological processes including protein synthesis, growth, rhythmic processes, immune defense, and vitellogenesis. Then, we identified many growth- and sex-related genes, including , , EF-hand family genes, , and . In addition, a total of 19,573 simple sequence repeats (SSRs) were screened and identified from the transcriptome sequences. The results of this study can provide valuable information on growth- and sex-related genes and facilitate further exploration of the molecular mechanism of sexual growth dimorphism.
Topics: Animals; Female; Male; Transcriptome; Molecular Sequence Annotation; Gene Expression Profiling; Fishes
PubMed: 36389430
DOI: 10.7717/peerj.14342 -
Frontiers in Physiology 2022Treatment with recombinant gonadotropin hormones (rGths), follicle-stimulating hormone (rFsh) and luteinizing hormone (rLh), was shown to induce and complete...
Treatment with recombinant gonadotropin hormones (rGths), follicle-stimulating hormone (rFsh) and luteinizing hormone (rLh), was shown to induce and complete vitellogenesis to finally obtain viable eggs and larvae in the flathead grey mullet (), a teleost arrested at early stages of gametogenesis in intensive captivity conditions. This study aimed to investigate the transcriptomic changes that occur in the ovary of females during the rGths-induced vitellogenesis. Ovarian samples were collected through biopsies from the same five females at four stages of ovarian development. RNASeq libraries were constructed for all stages studied, sequenced on an Illumina HiSeq4000, and a transcriptome was constructed. Differentially expressed genes (DEGs) were identified between stages and the functional properties of DEGs were characterized by comparison with the gene ontology and Kyoto Encyclopedia. An enrichment analysis of molecular pathways was performed. The transcriptome comprised 287,089 transcripts after filtering. As vitellogenesis progressed, more genes were significantly upregulated than downregulated. The rFsh application induced ovarian development from previtellogenesis to early-to-mid-vitellogenesis with associated pathways enriched from upregulated DEGs related to ovarian steroidogenesis and reproductive development cholesterol metabolism, ovarian growth and differentiation, lipid accumulation, and cell-to-cell adhesion pathways. The application of rFsh and rLh at early-to-mid-vitellogenesis induced the growth of oocytes to late-vitellogenesis and, with it, the enrichment of pathways from upregulated DEGs related to the production of energy, such as the lysosomes activity The application of rLh at late-vitellogenesis induced the completion of vitellogenesis with the enrichment of pathways linked with the switch from vitellogenesis to oocyte maturation. The DEGs and enriched molecular pathways described during the induced vitellogenesis of flathead grey mullet with rGths were typical of natural oogenesis reported for other fish species. Present results add new knowledge to the rGths action to further raise the possibility of using rGths in species that present similar reproductive disorders in aquaculture, the aquarium industry as well as the conservation of endangered species.
PubMed: 36388126
DOI: 10.3389/fphys.2022.1033445 -
Current Biology : CB Nov 2022The evolutionary origin of nutrient trafficking, a key development in metazoans, has been relatively unexplored. A new study in a model sea anemone exploits click...
The evolutionary origin of nutrient trafficking, a key development in metazoans, has been relatively unexplored. A new study in a model sea anemone exploits click chemistry and gene editing to provide insight into how nutrient trafficking may have arisen.
Topics: Animals; Vitellogenesis; Sea Anemones; Biological Evolution; Biological Transport; Nutrients
PubMed: 36347232
DOI: 10.1016/j.cub.2022.09.020 -
Animals : An Open Access Journal From... Oct 2022In teleost, as in other vertebrates, stress affects reproduction. A key component of the stress response is the pituitary secretion of the adrenocorticotropic hormone...
In teleost, as in other vertebrates, stress affects reproduction. A key component of the stress response is the pituitary secretion of the adrenocorticotropic hormone (ACTH), which binds to the melanocortin 2 receptor (MC2R) in the adrenal glands and activates cortisol biosynthesis. In zebrafish, Mc2r was identified in male and female gonads, while ACTH has been shown to have a physiological role in modulating reproductive activity. In this study, the hypothesis that other melanocortins may also affect how the zebrafish gonadal function is explored, specifically steroid biosynthesis, given the presence of members of the melanocortin signaling system in zebrafish gonads. Using cell culture, expression analysis, and cellular localization of gene expression, our new observations demonstrated that melanocortin receptors, accessory proteins, antagonists, and agonists are expressed in both the ovary and testis of zebrafish ( = 4 each sex). Moreover, melanocortin peptides modulate both basal and gonadotropin-stimulated steroid release from zebrafish gonads ( = 15 for males and = 50 for females). In situ hybridization in ovaries ( = 3) of zebrafish showed and in follicular cells and adjacent to cortical alveoli in the ooplasm of previtellogenic and vitellogenic oocytes. In zebrafish testes ( = 3), and were detected exclusively in germ cells, specifically in spermatogonia and spermatocytes. Our results suggest that melanocortins are, directly or indirectly, involved in the endocrine control of vitellogenesis in females, through modulation of estradiol synthesis via autocrine or paracrine actions in zebrafish ovaries. Adult zebrafish testes were sensitive to low doses of ACTH, eliciting testosterone production, which indicates a potential role of this peptide as a paracrine regulator of testicular function.
PubMed: 36290123
DOI: 10.3390/ani12202737