Life-history traits of the red brocade hermit crab Dardanus insignis on the subtropical Brazilian coast

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Vertical distribution by demographic groups of ghost crab Ocypode quadrata (Crustacea: Brachyura)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Developmental aspects of early pregnancy in mares

In mares, the embryo migrates to the uterus between days 5 and 6 postovulation beginning its mobility through all uterine segments, which is essential for the maternal recognition of pregnancy. During the mobility phase, the embryonic vesicle shows a linear growth rate until its fixation between days 15 and 17, when the orientation phenomenon occurs. From fixation to day 28 of pregnancy, the embryonic growth is less evident (plateau) by cross-section ultrasound examination. After this period the linear growth rate is reestablished until day 46. This plateau is attributed to the increased uterine tone that compresses the vesicle and to volume expansion, making it difficult to detect the conceptus growth only by the cross-section diameter. Around day 20, the embryo proper is visualized as an echogenic spot in the ventral aspect of the vesicle. Additionally, development of allantoic sac, embryonic heartbeat, yolk sac regression and posterior umbilical cord formation also can be visualized from days 20 to 40. An intimate interaction between uterus and conceptus is essential for the normal pregnancy development. Color-and spectral-Doppler ultrasonography can be useful for the evaluation of this interface. A gradual increase on uterine vascularity during the early pregnancy and transient changes in endometrial vascularity accompanying the vesicle location during the mobility phase have been described. Around day 38 of gestation, the formation of the endometrial cups begins and, consequently, the synthesis of the equine chorionic gonadotropin (eCG) induces the formation and development of supplementary corpora lutea, which are important to secrete progesterone and to maintain pregnancy until around day 120.

Reprodução de papagaio-verdadeiro (Amazona aestiva) em cativeiro: perfil anual de esteróides sexuais e ensaio de estímulo hormonal exógeno

Pós-graduação em Medicina Veterinária - FCAV

Impact of the medicine Hydroxyurea on reproduction and development, using Drosophila melanogaster as a model organism

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Carrying progeny on the back: reproduction in the Brazilian aquatic frog Pipa carvalhoi

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Endocrine and paracrine regulation of zebrafish spermatogenesis: the Sertoli cell perspective

Spermatogonial stem cells (SSCs) either self-renew or differentiate into spermatogonia that further develop into spermatozoa. Self-renewal occurs when residing in a specific micro-environment (niche) while displacement from the niche would tip the signalling balance towards differentiation. Considering the cystic type of spermatogenesis in fish, the SSC candidates are single type A undifferentiated (A(und)) spermatogonia, enveloped by mostly one niche-forming Sertoli cell. When going through a self-renewal cell cycle, the resulting new single type Aund spermatogonium would have to recruit another Sertoli cell to expand the niche space, while a differentiating germ cell cyle would result in a pair of spermatogonia that remain in contact with their cyst-forming Sertoli cells. In zebrafish, thyroid hormone stimulates the proliferation of Sertoli cells and of type Aund spermatogonia, involving Igf3, a new member of the Igf family. In cystic spermatogenesis, type Aund spermatogonia usually do not leave the niche, so that supposedly the signalling in the niche changes when switching from self-renewal to differentiation. and rzAmh inhibited differentiation of type A(und) spermatogonia as well as Fsh-stimulated steroidogenesis. Thus, for Fsh to efficiently stimulate testis functions, Amh bioactivity should be dampened. We also discovered that Fsh increased Sertoli cell Igf3 gene and protein expression; rzIgf3 stimulated spermatogonial proliferation and Fsh-stimulated spermatogenesis was significantly impaired by inhibiting Igf receptor signaling. We propose that in zebrafish, Fsh is the major regulator of testis functions and, supported by other endocrine systems (e.g. thyroid hormone), regulates Leydig cell steroidogenesis as well as Sertoli cell number and growth factor production to promote spermatogenesis.

Reproductive Plasticity in the Speckled Crab Arenaeus cribrarius (Decapoda, Brachyura, Portunidae) Associated with a Population Decline

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Meat yield of the mangrove crab, Ucides cordatus (Linnaeus, 1763) (Crustacea, Brachyura, Ucididae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphological and morphometric aspects of early life stages of piabanha Brycon gouldingi (Characidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relative growth and morphological sexual maturity of the mangrove crab Aratus pisonii (H. Milne Edwards, 1837) (Decapoda, Brachyura, Sesarmidae) on the southern coast of the state of Sao Paulo, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The population structure of two sympatric hermit-crab species on a subtidal rocky shore of an island in southeastern Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fluorescent antibody test, quantitative polymerase chain reaction pattern and clinical aspects of rabies virus strains isolated from main reservoirs in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Breeding season diet of Scarlet Ibises and Little Blue Herons in a Brazilian mangrove swamp

We studied the diet composition and overlap of Scarlet Ibises (Eudocimus ruber) and Little Blue Herons (Egretta caerulea in a mangrove swamp in southeast Brazil during the 1996-1997 breeding season, which occurs during the rainiest period. Crabs comprised 95% of all prey taken by the ibises and 80% of the prey of the herons, Nevertheless, diet overlap was small (similar to 30%) due to ibises feeding mostly on Uca spp. and Eurythium limosum crabs, which were taken from their burrows; the herons fed on the arboreal and semi-arboreal Aratus Pisonii and Metasesarma rubripes crabs. Divergent hunting strategies of ibises (tactile foragers) and herons visually-oriented predators) explains the diet segregation when preying on an ecologically diverse crab guild, but it is unclear why herons prey rarely on fiddler crabs. Scarlet Ibises bred successfully while feeding oil estuarine organisms living in low salinities in the mangroves, showing that mangroves may be adequate foraging habitats for chick-rearing ibises during periods of low salinity.

Heat stress induced alteration in bovine oocytes: functional and cellular aspects

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)