Banca de DEFESA: KADIGNA CARLA SILVA COSTA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : KADIGNA CARLA SILVA COSTA
DATA : 27/12/2016
HORA: 08:30
LOCAL: Sala dos Embriões
TÍTULO:

Morphofunctional analysis of the testis and spermatogenic process of the bat Artibeus planirostris.

PALAVRAS-CHAVES:

Reproduction in bats, Seminiferous tubules, Leydig cells, Morphometry.

PÁGINAS: 60
GRANDE ÁREA: Ciências Biológicas
ÁREA: Morfologia
SUBÁREA: Histologia
RESUMO:

Bats act in several ways to regulate ecosystems. Among its representatives, Artibeus planirostris is a frugivorous species, which acts both as a seed disperser and as a pollinator. Due to the scarcity of studies on the reproductive biology of bats, especially in males, and the lack of information on the reproduction of mammals belonging to the Northeast region of Brazil, this study aimed to quantify the spermatogenic process of A. planirostris, as well as its seasonal variation, through the morphological and morphometric analysis of the testes. The animals were collected in the years of 2013 and 2014, between the dry (n = 10) and rainy seasons (n = 10), at the central campus of the Federal University of Rio Grande do Norte (Natal-RN). After euthanasia, the testes were collected and processed histologically for embedding in historesin and analyzed under light microscopy. The histological slides were photographed and the morphometry was done using the Image-Pro Plus software. The results of morphometry and biometry were compared by the Kruskall Wallis test or the t test, with a significance level of 5% (p <0.05). Considering the two seasons, the animals had a mean gonadosomatic index of 0,54%. The seminiferous tubules represented about 92% of the testicular parenchyma, the remaining being represented by the intertubule. The seminiferous tubules were composed of about 27% of lumen, 60% of seminiferous epithelium and 4% of tunica propria. Among the analyzed morphometric parameters, only the lumen showed significant variation between the seasons, so that the highest percentage was found in the rainy season. The tubular diameter and height of the seminiferous epithelium presented a mean of 142 μm and 43 μm, respectively. It was obtained a mean tubular length per gram of testis of 64.7 m and tubulesomatic index of 0.47%. The cell population of the seminiferous epithelium was composed of spermatogonia type A, primary spermatocytes in the transition from pre-leptotene to leptotene, zygotene and pachytene, rounded spermatids and Sertoli cells. Only the population of primary spermatocytes in pre-leptotene/leptotene presented variation between seasons, with higher values in the dry season. The annual mitotic index was 14%, the meiotic index was 3%, the overall spermatogenesis yield was 51 cells and the Sertoli cell index was 6 cells. The analysis of the frequency of the stages that compose the seminiferous epithelium cycle showed that the most and least frequent stages were, respectively, the 1 and the 6. Stages 1 and 4 varied statistically between seasons, with stage 1 being more frequent in the rainy season and stage 4 being more frequent in the dry season. The intertubule was predominantly composed of Leydig cells, which presented higher percentages in the testicular parenchyma in the dry season, as well as the volumetric proportion of the lymphatic vessels. The other intertubular components did not vary statistically between the seasons, as well as the parameters analyzed for Leydig cell morphometry. These cells presented a number per gram of testis with an annual mean of 5,63x107 cells and a Leydyssomatic index of 0.005%. Large investment in seminiferous tubules, with low support capacity by Sertoli cells, and great investment in Leydig cells in the testicular parenchyma were observed, especially in the dry season, as well as in the pre-leptotene/leptotene primary spermatocyte population. It is concluded that A. planirostris presented a testicular pattern similar to that of other bats, as well for other mammals, and has an annual continuous spermatogenic pattern in the Northeast of the country.

MEMBROS DA BANCA:
Interno - 1330828 - CARLOS EDUARDO BEZERRA DE MOURA
Presidente - 1718086 - DANIELLE BARBOSA MORAIS
Externo à Instituição - SERGIO LUIS PINTO DA MATTA - UFV