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Memorias Do Instituto Oswaldo Cruz 1993The eggs from oviparous organisms contain large amounts of vitellus, or yolk, which are utilized by the growing embryo. Vitellogenesis is the process of vitellus... (Review)
Review
The eggs from oviparous organisms contain large amounts of vitellus, or yolk, which are utilized by the growing embryo. Vitellogenesis is the process of vitellus accumulation and involves massive heterosynthetic synthesis of the protein vitellogenin (Vg) and its deposition in the oocyte. This work summarizes data on Vg structure, synthesis, uptake by oocytes and its fate during embryogenesis. The hormonal control of vitellogenesis and its tissue, sex and temporal regulation are also discussed. Where it is available, data on structure and expression of Vg-coding genes are reviewed. Insect vitellogenesis is priorized although other oviparous animal groups outside insects are also treated.
Topics: Animals; Oogenesis; Vitellogenesis; Vitellogenins
PubMed: 8246743
DOI: 10.1590/s0074-02761993000100005 -
Developmental Biology (New York, N.Y. :... 1985
Review
Topics: Animals; Oogenesis; Vertebrates; Vitellogenesis
PubMed: 3917200
DOI: 10.1007/978-1-4615-6814-8_3 -
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 -
Developmental Biology (New York, N.Y. :... 1985
Review
Topics: Animals; Gene Expression Regulation; Insecta; Ovum; Vitellogenesis
PubMed: 3917207
DOI: 10.1007/978-1-4615-6814-8_2 -
Molecular and Cellular Endocrinology Jun 2024The endocrine system plays a pivotal role in shaping the mechanisms that ensure successful reproduction. With over a million known insect species, understanding the... (Review)
Review
The endocrine system plays a pivotal role in shaping the mechanisms that ensure successful reproduction. With over a million known insect species, understanding the endocrine control of reproduction has become increasingly complex. Some of the key players include the classic insect lipid hormones juvenile hormone (JH) and ecdysteroids, and neuropeptides such as insulin-like peptides (ILPs). Individual endocrine factors not only modulate their own target tissue but also play crucial roles in crosstalk among themselves, ensuring successful vitellogenesis and oogenesis. Recent advances in omics, gene silencing, and genome editing approaches have accelerated research, offering both fundamental insights and practical applications for studying in-depth endocrine signaling pathways. This review provides an updated and integrated view of endocrine factors modulating vitellogenesis and oogenesis in insect females.
Topics: Animals; Female; Vitellogenesis; Oogenesis; Insecta; Juvenile Hormones; Endocrine System
PubMed: 38494046
DOI: 10.1016/j.mce.2024.112211 -
International Review of Cytology 2004The comparative approach on how and when vitellogenesis occurs in the diverse reproductive strategies displayed by aquatic and terrestrial lower vertebrates is presented... (Review)
Review
The comparative approach on how and when vitellogenesis occurs in the diverse reproductive strategies displayed by aquatic and terrestrial lower vertebrates is presented in this chapter; moreover, attention has been paid to the multihormonal control of hepatic vitellogenin synthesis as it is related to seasonal changes and to vitellogenin use by growing oocytes. The hormonal mechanisms regulating vitellogenin synthesis are also considered, and the effects of environmental estrogens on the feminization process in wildlife and humans have been reported. It is then considered how fundamental nonmammalian models appear to be, for vitellogenesis research, addressed to clarifying the yolkless egg and the evolution of eutherian viviparity.
Topics: Amphibians; Animals; Female; Feminization; Fishes; Gonads; Hazardous Substances; Hormones; Hypothalamo-Hypophyseal System; Male; Reproduction; Reptiles; Vitellogenesis; Vitellogenins
PubMed: 15464851
DOI: 10.1016/S0074-7696(04)39001-7 -
The Journal of Experimental Zoology.... 1990The stimulation of yolk protein synthesis by estrogen is a characteristic of female non-mammalian vertebrates; in mammals, or their reptilian ancestors, however,... (Review)
Review
The stimulation of yolk protein synthesis by estrogen is a characteristic of female non-mammalian vertebrates; in mammals, or their reptilian ancestors, however, vitellogenesis has been suppressed as a corollary of the evolution of viviparity. It is our hypothesis that progesterone has a dual role in this phylogenetic trend: a) to inhibit myometrial contraction and thus set the stage for internal development of embryos and associated placentation and b) to inhibit yolk protein synthesis in a coordinate manner as placentation became an efficient direct supply of nutrients to the fetus. Despite the absence of vitellogenesis per se in eutherian mammals, significant sex-differentiated hepatic protein-lipid synthetic functions remain, which are under complex hormonal control. We have presented evidence that in the reptiles, the central vertebrate group from which the ancestors of modern mammals evolved, the control of yolk protein synthesis is also complex, involving both pituitary hormones (GH, PRL, and LH) and ovarian steroids (estradiol, testosterone, and progesterone). Adequate evidence exists to suggest that mammalian hepatic lipoprotein synthesis and its regulatory elements are phylogenetically derived from their reptilian ancestors and may be better understood in this context. This is of particular relevance to cardiovascular disease in which there is a clear sex bias yet for which no coordinated research program exists which takes into account the relevant phylogenetic history. We believe that reptilian, and possibly avian, models could be used to great advantage to probe the endocrine components of cardiovascular disease.
Topics: Animals; Biological Evolution; Egg Proteins; Estradiol; Female; Hormones; Humans; Invertebrates; Lipoprotein Lipase; Lipoproteins; Liver; Male; Mammals; Models, Biological; Progesterone; Reptiles; Sex Characteristics; Vitellogenesis
PubMed: 1974771
DOI: 10.1002/jez.1402560418 -
General and Comparative Endocrinology Jun 2021The Patagonian toothfish (Dissostichus eleginoides) is a new promising fish species for diversifying the aquaculture industry in Chile because of its high economic value...
The Patagonian toothfish (Dissostichus eleginoides) is a new promising fish species for diversifying the aquaculture industry in Chile because of its high economic value and high international demand. However, when attempting to start aquaculture of a new species, one of the major challenges is successfully achieving conditions to reproduce them. This is particularly difficult when the information on the biology and physiology of the reproduction process of the species in question is scarce, as is the case with D. eleginoides. Additionally, female reproductive dysfunction is more prevalent under culture conditions and it is very important to have tools to evaluate the progress of oocyte maturation. Therefore, evaluation of the vitellogenesis process in addition to measuring gonadosomatic index (GSI) and oocyte diameter is an important parameter for allowing the monitoring of females from a broodstock that will spawn in the reproductive season. This study aimed to develop an enzyme-linked immunosorbent assay (ELISA) specific for the Patagonian toothfish (D. eleginoides) vitellogenine (Vtg) and quantify the plasma level in the fishes, maintained in a recirculation aquaculture system (RAS), throughout their reproductive cycle. A polyclonal antibody was prepared using the isolated major egg protein as antigen. This antibody was specific to the major plasma phosphoprotein identified as Vtg and was used to develop and standardize an indirect ELISA assay. The assay standard curve was linear from 0.1 to 1 µg/ml purified egg yolk protein and the average r was 0.995. We corroborated our ELISA assay by demonstrating a strong correlation between high levels of plasma Vtg obtained by the assay and the intensity of the corresponding bands in both SDS-PAGE coomassie stained gels and Western Blot. During the two reproductive seasons analyzed, the highest Vtg plasma level was obtained in the majority of the females in the last three months before spawning (December-January). This differs from the wild population in which the spawning occurs during the austral winter (June-September). Therefore, the RAS condition established to maintain in captivity the D. eleginoides allows females to develop mature oocytes normally, as was evidenced by picks of Vtg plasma levels.
Topics: Animals; Aquaculture; Female; Fishes; Perciformes; Reproduction; Vitellogenesis; Vitellogenins
PubMed: 33794273
DOI: 10.1016/j.ygcen.2021.113768 -
Environmental Health Perspectives Oct 1995A rapidly increasing number of chemicals, or their degradation products, are being recognized as possessing estrogenic activity, albeit usually weak. We have found that... (Review)
Review
A rapidly increasing number of chemicals, or their degradation products, are being recognized as possessing estrogenic activity, albeit usually weak. We have found that effluent from sewage treatment works contains a chemical, or mixture of chemicals, that induces vitellogenin synthesis in male fish maintained in the effluent, thus indicating that the effluent is estrogenic. The effect was extremely pronounced and occurred at all sewage treatment works tested. The nature of the chemical or chemicals causing the effect is presently not known. However, we have tested a number of chemicals known to be estrogenic to mammals and have shown that they are also estrogenic to fish; that is, no species specificity was apparent. Many of these weakly estrogenic chemicals are known to be present in effluents. Further, a mixture of different estrogenic chemicals was considerably more potent than each of the chemicals when tested individually, suggesting that enhanced effects could occur when fish are exposed simultaneously to various estrogenic chemicals (as is likely to occur in rivers receiving effluent). Subsequent work should determine whether exposure to these chemicals at the concentrations present in the environment leads to any deleterious physiological effects.
Topics: Animals; Biomarkers; Environmental Monitoring; Estrogens; Fishes; Male; Phylogeny; Sewage; Vitellogenesis; Water Pollutants, Chemical
PubMed: 8593867
DOI: 10.1289/ehp.95103s7173 -
International Journal For Parasitology Jun 2000Vitellocytes have two important functions in cestode embryogenesis: (1) formation of hard egg-shell (e.g. Pseudophyllidea) or a delicate capsule (e.g. Cyclophyllidea),... (Comparative Study)
Comparative Study Review
Vitellocytes have two important functions in cestode embryogenesis: (1) formation of hard egg-shell (e.g. Pseudophyllidea) or a delicate capsule (e.g. Cyclophyllidea), and (2) supplying nutritive reserves for the developing embryos. During evolution any of these two functions can be reduced or intensified in different taxa depending on the type of their embryonic development, degree of ovoviviparity and life cycles. Within the Cestoda, there are three monozoic taxa with only one set of genital organs: Amphilinidea, Gyrocotylidea and Caryophyllidea. In these monozoic taxa and some polyzoic groups with well developed vitellaria (e.g. Pseudophyllidea, Trypanorhyncha) a single oocyte [=germocyte] and a large number of vitellocytes (up to 30) are enclosed within a thick, hardened egg-shell, forming a type of eggs typical for the basic pattern of Neodermata. Only one type of egg-shell enclosures, the so-called 'heterogeneous shell-globule vesicle' is common for the above mentioned cestode taxa. Each membrane-bounded vesicle of mature vitellocytes contains numerous electron-dense shell globules embedded in a translucent matrix. In free-living Neoophora and Monogenea there are two types of vesicles with dense granules; the second is considered to be proteinaceous reserve material. Within the Cestoda, the numbers of vitellocytes per germocyte are reduced in those taxa forming eggs of the 'Cyclophyllidean-type' (e.g. Cyclophyllidea, Tetraphyllidea, Pseudophyllidea). This is particularly evident in Cyclophyllidea; for example, in vitellocytes of Hymenolepis diminuta (Hymenolepididae) there are numerous vitelline granules of homogeneously electron-dense material; in Catenotaenia pusilla (Catenotaeniidae) there are three large, homogenous vitelline vesicles, while in Inermicapsifer madagascariensis (Anoplocephalidae) there is only one large vitelline vesicle, containing homogeneously electron-dense material, which occupies most of the vitelline cell volume. In this respect the Tetraphyllidea and Proteocephalidea, in forming eggs that lack a hard egg-shell, hold an intermediate position. A comparison of interrelationships which exist among types of vitellocytes, vitellogenesis, types of embryonic development, ovoviviparity and life cycles indicates parallelisms and analogies in adaptation to the parasitic way of life in different groups of cestodes. Knowledge on cestode vitellogenesis may also have an important applied aspect. Vitellocytes, due to their high metabolic rate, represent a very sensitive target for analysing effect of anthelminthic drugs upon the egg formation (ovicidal effects); rapid degeneration of vitellocytes is usually accompanied by a cessation of egg production.
Topics: Animals; Cestoda; Fatty Acids, Unsaturated; Female; Glycogen; Life Cycle Stages; Oocytes; Vitellogenesis
PubMed: 10899525
DOI: 10.1016/s0020-7519(00)00066-7