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Mostrando ítems 421-430 de 727
Noncanonical wnt signaling in the integrity of the blood-testis barrier and sperm release
(Endocrine Society, 2021-10)
The mammalian testis is formed by 2 morphologically and functionally distinct compartments: the seminiferous tubules and the interstitial tissue. The seminiferous tubules contain the germ cell population, originating the ...
Functional morphology of the male reproductive system in Callichirus major (Crustacea: Decapoda: Axiidea): Evidence of oocytes in the gonad
(Wiley Blackwell Publishing, Inc, 2018-01)
Callichirus major inhabits the intertidal region of marine ecosystems and it is frequently used as live bait for fishing. This study aimed to describe the functional anatomy of the male reproductive system by microscopic ...
Seasonal variations cause morphological changes and altered spermatogenesis in the testes of viscacha (Lagostomus maximus)
(Elsevier Science, 2014-06)
This study complements the previous investigations of the reproductive biology of maleviscachas, a rodent of a seasonal Hystricognathi that exhibits photoperiod-induced morpho-logical variations in the reproductive system. ...
Gametogenic cycle of the tropical vermetids Eualetes tulipa and Dendropoma corrodens (Mollusca: Caenogastropoda: Vermetidae)
(Cambridge University Press, 2010-05)
The population density, annual gametogenic cycle, and size at sexual maturity of two vermetid species, Eualetes tulipa (invasive) and Dendropoma corrodens was studied in the southern Caribbean at the Planta Centro power ...
Estradiol and reproduction in the South American toad Rhinella arenarum (Amphibian, Anura)
(Academic Press Inc Elsevier Science, 2019-03)
Rhinella arenarum is a South American toad with wide geographic distribution. Testes of this toad produce high amount of androgens during the non reproductive season and shift steroid synthesis from androgens to 5α-pregnanedione ...
Anatomy and Histology of the Male Reproductive Tract and Spermatogenesis Fine Structure in the Lesser Anteater ( Tamandua tetradactyla , Myrmecophagidae, Xenarthra): Morphological Evidences of Reproductive Functions
(Wiley Blackwell Publishing, Inc, 2013-08)
The anatomy and histology of the male genital tract of the lesser anteater were studied. Fine details of spermatozoa regarding their genesis and morphology were also studied in six adult specimens. The testes lie in the ...
The making of abnormal spermatozoa: Cellular and molecular mechanisms underlying pathological spermiogenesis
(Springer, 2010-09)
Fertilization in mammals occurs via a series of well-defined events in the secluded environment of the female reproductive tract. The mode of selection of the fertilizing spermatozoon nevertheless remains unknown. As has ...
Spermatogenesis, Spermatophore, and Seminal Fluid Production in the Adult Blue Crab Callinestes danae (Portunidae)
(Oxford University Press, 2012-01)
Sperm and spermatophore production in Callinectes danae Smith, 1869 were examined by histochemistry and correlated with gonadosomatic (GSI) and hepatosomatic (HSI) indices. The GSI from developing (DE) and mature (MAT) ...
Hibridação natural entre duas espécies de lambaris na cabeceira do Rio Grande e suas consequências na gametogênese e morfologia gonadal dos híbridos
(Universidade Federal de Minas GeraisBrasilICB - DEPARTAMENTO DE MORFOLOGIAPrograma de Pós-Graduação em Biologia CelularUFMG, 2021-01-29)
Hybridization is a relevant process for ecology, conservation and evolution of species, but its occurrence and consequences on the biology of hybrids are still poorly studied. In addition, although it is an event that ...
Transplantes singênico e xenogênico de espermatogônias troncos em gatos doméstico (Felis catus) adultos.
(Universidade Federal de Minas GeraisUFMG, 2009-11-30)
Similar to most wild felids, the ocelot (Leopardus pardalis) is an endangered species. Aggravating this situation, knowledge on the reproductive biology of the ocelot is very limited. Germ cell transplantation is an effective ...