Africanized honeybee (Apis mellifera) semen freezing using Tris-based and Collins extenders

This study is aimed at evaluating the effect of different extenders on the cryopreservation of semen from Africanized honeybees (A. mellifera). Semen from honeybee drones from 10 different colonies was obtained by endophallus exposure technique and immediately evaluated for motility, viability using fluorescent probes, functional membrane integrity using the water test, and morphology. Samples from each colony were divided in three aliquots and subjected to a dilution ratio of 12:1 (diluent: semen) using Tris, Tris + egg yolk (Tris+EY), and Collins extender. Samples were cryopreserved and stored in liquid nitrogen for one week and then rewarmed and reevaluated. Immediate dilution provoked no significant effect on sperm motility and functional membrane integrity, regardless of the extender used; however, the greatest values (P < 0.05) for normal sperm morphology were found at the use of isolate Tris (69.3 ± 1.9%). After thawing, there were no significant differences among extenders with relation to the preservation of sperm motility, viability, and functional membrane integrity, but the Tris extender provided the highest post-thawing values (P < 0.05) for sperm normal morphology (49.2 ± 4.9%) while the Collins extender provoked the highest amounts (P < 0.05) of curled tail defects (67.5 ± 3.2%). Moreover, the Tris was the only extender at preserving the proportion of normal sperm after thawing similar to what was verified for fresh samples. In summary, we suggest the use of a Tris-based extender for the cryopreservation of Africanized honeybee semen.

Short-term preservation of canine sperm-binding ability and other metrics using the INRA-96 in comparison to Tris-egg yolk extender

The use of assisted reproductive techniques, such as chilled semen, contributes to the maintenance and genetic improvement of canine breeding. The INRA-96 extender is a commercially available, chemically defined medium that was initially developed for the preservation of equine semen and exhibits preservation potential in the canine species. This research aims to evaluate the INRA-96 extender as an alternative for the short-term preservation of canine semen in terms of sperm quality parameters such as motility and kinetic parameters, integrity and functionality of the plasma membrane in fresh and chilled-rewarmed samples, as well as the sperm-binding ability using the perivitelline membrane of the chicken egg as an indicator of the fertilizing capacity of the preserved semen. A total of 18 ejaculates from 9 French bulldogs (two ejaculates per dog) were collected and divided into two aliquots that were diluted in Tris-egg yolk 20% (control) or INRA-96 to a final concentration of 100 × 106 sperm/mL. Samples were refrigerated in a biological incubator at 5°C and evaluated at 0, 24 and 48 h time points. Comparing the two treatments after 48 h of refrigeration, both extenders showed similar values (p < .5) for the majority of kinetic parameters, with the INRA-96 group promoting a total motility of 88.1 ± 2.9%. In addition, the morphology, integrity and functionality of the plasma membrane were preserved above 70% in this group. Dilution with INRA-96 also provided a significantly higher amount of sperm bound (256.2 ± 21.1) to the perivitelline membrane of the egg yolk compared to the sperm-binding rates (p < .05) achieved at the use of Tris-egg yolk (215.2 ± 21 bound spermatozoa) at 48 h. Our study proved similar functional properties of dog sperm cells treated with INRA-96 in comparison to commonly used home-made Tris-based extender during short-time storage.

Cryopreservation of Spix's yellow-toothed cavy epididymal sperm using Tris- and coconut water-based extenders supplemented with egg yolk or Aloe vera

Addressing the establishment of biobanks for the conservation of wild hystricomorph rodents' germplasm, we verified the effects of different extenders and distinct concentrations of non-permeant cryoprotectants on the sperm parameters of Spix's yellow-toothed cavies. Nine testis-epididymis complexes were used for sperm collection by retrograde washing using Tris or a powdered coconut water extender (ACP®-116c). Spermatozoa were diluted and frozen with the same extenders supplemented with egg yolk or Aloe vera at a 10% or 20% concentration. After recovery and cryopreservation, all samples were evaluated for sperm kinetic parameters, morphology, membrane integrity, osmotic response, and sperm-binding capability using an egg yolk perivitelline membrane assay. After recovery, no differences were observed between Tris and ACP®-116c that provided 515.4 × 10⁶ sperm/mL and 561.6 × 10⁶ sperm/mL, presenting >65% motile sperm, respectively. After cryopreservation, most effective preservation of sperm kinetic parameters (68.1 ± 5.9% motile sperm) and membrane integrity (48.2 ± 7.4%) was provided by Tris extender supplemented with 10% egg yolk. However, both extenders supplemented with any concentration of egg yolk or Aloe vera presented similar preservation of osmotic response and sperm-binding ability after cryopreservation. In summary, we suggest the use of a Tris extender supplemented of 10% egg yolk for cryopreservation of Spix's yellow-toothed cavy epidydimal sperm.

Inovação em instituição militar de pesquisa: um estudo de caso exploratório

As instituições públicas de pesquisa são componentes essenciais do sistema nacional de inovação e, no caso de instituições militares, atuam como veículos por meio dos quais países em desenvolvimento podem adquirir conhecimento e competência sobre tecnologias industriais. O presente trabalho examina a presença de fatores de gestão favoráveis à inovação em instituições militares de pesquisa. A abordagem foi qualitativa e exploratória e, além das fontes bibliográficas, teóricas e empíricas, foi feita pesquisa de campo, através de observação direta, da aplicação de questionários baseados na auditoria de processos de gestão da inovação propostos por Tidd, Bessant e Pavitt (2008) e de entrevistas abertas com a intenção de validar o desenho da pesquisa. O resultado mostrou em ambas as instituições examinadas a presença dos componentes que caracterizam uma organização inovadora, com predominância das características da condição estável e, em menor dimensão, da inovação de ruptura. Foram detectadas diferenças entre as instituições, atribuíveis a características de natureza organizacional, de sistemas internos de comunicação e de regimes tecnológicos diferenciados com reflexo sobre as concepções acerca do conceito e da dinâmica da inovação.