GnRH agonist in association with hCG versus hCG alone for final oocyte maturation triggering in GnRH antagonist cycles.

Objective: To analyze gonadotropin-releasing hormone (GnRH) agonist in association with human chorionic gonadotropin (hCG) (dual triggering) versus hCG alone (conventional triggering) for final oocyte maturation triggering in GnRH antagonist cycles in an unselected population of Brazilian women.

Methods: This prospective case-control study involved 114 patients referred to autologous in vitro fertilization treatment between February 2018 and August 2019, recruited regardless of age, infertility factor or number of cycles. The patients were randomly allocated into two groups according to oocyte maturation triggering approach: group A (n = 48) - hCG only; and group B (n = 66) - hCG plus GnRH agonist.

Redescription of Astyanax gymnogenys Eigenmann, 1911 (Characiformes: Characidae), a senior synonym of Astyanax longirhinus Garavello amp; Sampaio, 2010.

Astyanax gymnogenys Eigenmann was described from the middle rio Iguaçu basin, based on two specimens and A. longirhinus Garavello Sampaio was described from the upper, middle and lower rio Iguaçu, based on several specimens. Due to their morphological similarity, including overlapping diagnostic characters between the two nominal species, allied to their occurrence in the same basin, doubts of their validity as independent taxa emerged.

Morphologically Cryptic Species of the Astyanax bimaculatus "Caudal Peduncle Spot" Subgroup Diagnosed Through Cytogenetic Characters.

Astyanax is a species-rich polyphyletic genus distributed between the southern United States and central Argentina. The genus contains groups of cryptic species, which are difficult to distinguish, and are sometimes identified wrongly. Basic and molecular cytogenetic analyses were run on Astyanax abramis and three junior synonyms of Astyanax lacustris: Astyanax altiparanae, from the upper Paraná River basin, Astyanax asuncionensis, from the lower Paraná basin, and Astyanax jacuhiensis, from the upper Uruguay River.

Viability of homologous and heterologous subcutaneous transplantation of fresh germ cells in rabbits.

Objective: This study aimed to compare heterologous to homologous transplantation of fresh ovarian germ cells in rabbits.

Methods: Twelve female white New Zealand rabbits (Oryctolagus cuniculus) were randomly numbered and submitted to bilateral oophorectomies. The ovaries from the six odd-numbered rabbits were dissected and cortical germinal tissue was digested in collagenase type 1 to obtain six solutions containing stromal and germ cells, which were injected in the abdominal region of the odd-numbered rabbits themselves (homologous transplantation) and of the even-numbered rabbits (heterologous transplantation) off immunosuppression.

Highlighting Astyanax Species Diversity through DNA Barcoding.

DNA barcoding has been used extensively to solve taxonomic questions and identify new species. Neotropical fishes are found in a wide variety of shapes and sizes, with a large number of species yet to be described, many of which are very difficult to identify. Characidae is the most species-rich family of the Characiformes, and many of its genera are affected by taxonomic uncertainties, including the widely-distributed, species-rich genus Astyanax.