Birba Agustina, Ramallo Martín Roberto, Lo Nostro Fabiana, Guimarães Moreira Renata, Pandolfi Matías
Laboratorio de Neuroendocrinología y Comportamiento, DBBE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (C1428EHA), Buenos Aires, Argentina.
Laboratorio de Neuroendocrinología y Comportamiento, DBBE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (C1428EHA), Buenos Aires, Argentina; IBBEA-CONICET-UBA, Ciudad Universitaria (C1428EHA), Buenos Aires, Argentina.
Gen Comp Endocrinol. 2015 Sep 15;221:193-200. doi: 10.1016/j.ygcen.2015.02.004. Epub 2015 Feb 14.
The South American cichlid fish Cichlasoma dimerus presents a high breeding frequency and biparental care of the eggs and larvae. The male parental care period was divided in four different phases according to the developmental degree of the offspring: pre-spawning activity (MP, day 0), guarding eggs (ME, one day after fertilization (1 DAF)), guarding hatched larvae (MHL, 3 DAF), and guarding swimming larvae (MSL, 8 DAF). The aim of this study was to characterize male reproductive physiology by measuring steroid hormone plasma levels and analyzing testes cellular composition. Males exhibiting pre-spawning activity showed 8.4 times higher 11-ketotestosterone and 5.63 times higher testosterone levels than MHL. No differences were observed in estradiol and cortisol levels among the different phases. The cellular composition of the testes varied during the reproductive and parental care periods. Testes of MP were composed of 50% of spermatozoa, whereas spermatogonia type B and spermatocytes were predominant in the subsequent parental phases. A morphometric analysis of Leydig cells nuclear area revealed that MP and ME's Leydig cells averaged 1.27 times larger than that those of MHL and MSL and was positively correlated with circulating 11-KT and T levels. Hence, C. dimerus males showed important changes in its hormonal profiles and testicular cellular composition throughout the reproductive and parental care period.
南美丽鱼科鱼类双斑丽鲷具有较高的繁殖频率，并且亲鱼双方都会照顾鱼卵和幼鱼。根据后代的发育程度，雄鱼的亲代照顾期分为四个不同阶段：产卵前活动期（MP，第0天）、护卵期（ME，受精后一天（1 DAF））、护幼鱼期（MHL，3 DAF）和护游幼鱼期（MSL，8 DAF）。本研究的目的是通过测量血浆类固醇激素水平和分析睾丸细胞组成来表征雄性生殖生理学特征。表现出产卵前活动的雄鱼，其11-酮睾酮水平比护幼鱼期雄鱼高8.4倍，睾酮水平高5.63倍。不同阶段的雌二醇和皮质醇水平未观察到差异。在生殖和亲代照顾期间，睾丸的细胞组成有所变化。产卵前活动期的睾丸由50%的精子组成，而在随后的亲代阶段，B型精原细胞和精母细胞占主导。对睾丸间质细胞的核面积进行形态计量分析发现，产卵前活动期和护卵期的睾丸间质细胞平均比护幼鱼期和护游幼鱼期的大1.27倍，且与循环中的11-KT和T水平呈正相关。因此，双斑丽鲷雄鱼在整个生殖和亲代照顾期间，其激素水平和睾丸细胞组成都发生了重要变化。
