Ángel García-López

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Despite the fact that the Senegalese sole Solea senegalensis is a target species for the aquaculture industry in Spain and Portugal, very little is known about its gametogenesis and especially about testicular development. Therefore, the male reproductive system in adult S. senegalensis was described using a histological and histochemical approach. Mean(More)
Testicular development and plasma levels of sex steroids (11-ketotestosterone (11-KT), testosterone (T) and 17,20beta-dihydroxy-4-pregnen-3-one (17,20beta-P)) were investigated for the first time in cultured male Senegalese sole Solea senegalensis. The germ cell dynamics and gonadosomatic index (IG) were monitored. Based on the relative abundance of the(More)
Progestagenic sex steroid hormones play critical roles in reproduction across vertebrates, including teleost fish. To further our understanding of how progesterone modulates testis functions in fish, we set out to clone a progesterone receptor (pgr) cDNA exhibiting nuclear hormone receptor features from zebrafish testis. The open reading frame of pgr(More)
The osmoregulatory and metabolic role of testosterone (T) in the euryhaline teleost Sparus auratus was examined. Fish were implanted with a slow-release coconut oil implant alone (control) or containing T (2 or 5microgg(-1) body weight) and sampled 1, 3, and 7 days after implantation. Gill Na(+),K(+)-ATPase activity increased in fish treated with the lower(More)
This study aimed to improve, using the zebrafish model, our understanding of the distinct roles of pituitary gonadotropins FSH and LH in regulating testis functions in teleost fish. We report, for the first time in a vertebrate species, that zebrafish Leydig cells as well as Sertoli cells express the mRNAs for both gonadotropin receptors (fshr and lhcgr).(More)
The testis is a tightly controlled dynamic tissue. In mammals, there is growing evidence that estrogen plays a role in the regulation of testicular functions. In teleosts, high levels of 17beta-estradiol (E2) in serum correlate with the end of spermatogenesis, spawning, and the initiation of postspawning stages when spermatogonia are the main cell types in(More)
The gilthead seabream is a protandrous hermaphrodite seasonal breeding teleost with a bisexual gonad that offers an interesting model for studying the two first reproductive cycles (RCs), in which the specimens develops as males. During the first RC (RC1), 11-ketotestosterone (11-KT) and testosterone (T), the main androgens in fish, play different and(More)
A real-time PCR-based gene expression survey was performed on isolated European sea bass follicles from primary growth to late vitellogenesis. Expression levels of 18 transcripts with demonstrated relevance during oogenesis, encoding gonadotropin, thyrotropin, estrogen, androgen, and vitellogenin receptors, steroidogenesis-related as well as growth and(More)
The localization and characterization of oligosaccharide sequences in the testis of Senegalese sole Solea senegalensis was investigated using 12 lectins in combination with KOH saponification and sialidase digestion (K-s). The interstitial compartment contained all the sugar residues investigated, those bearing oligosaccharides terminating with sialic acid(More)
To develop new tools to study the regulation of testis physiology in teleost fish, a medium-term ex vivo organ culture system was adopted for zebrafish testis tissue. The addition of 100nM 11-ketotestosterone to the system supported complete spermatogenesis, as determined by morphological, molecular and immunohistochemical analyses. Under basal conditions,(More)