Abstract Sperm cells rely on different substrates to fulfil thei energy demand for different functions and diverse moments of their life. Species specific mechanism involve both energy substrate transport and their utilization: hexose transporters, a protein family of facilitative passive transporters of glucose and other hexose, have been identified in spermatozoa of different species and, within the species, their localization has been identified and, in some cases, linked to specific glycilitic enzyme presence. The catabolism of hexose sources for energy purposes has been studied in various species, and recent advances has been made in the knowledge of metabolic strategies of sperm cells. In particular, the importance of aerobic metabolism has been defined and described in horse, boar and even mouse spermatozoa; bull sperm cells demonstrate to have a good adaptability and capacity to switch between glycolysis and oxidative phosphorylation; finally, dog sperm cells have been demonstrated to have a great plasticity in energy metabolism management, being also able to activate the anabolic pathway of glycogen syntesis. In conclusion, the study of energy management and mitochondrial function in spermatozoa of different specie furnishes important base knowledge to define new media for preservation as well as newbases for reproductive biotechnologies. life utilization cases presence particular horse phosphorylation finally syntesis conclusion biotechnologies

Milkborne transmission of Shiga toxin- producing Escherichia coli (STEC) has raised considerable concern due to recent outbreaks worldwide and poses a threat to public health. The aim of this study was to develop a sensitive and specific multiplex PCR assay to detect the presence of STEC in bovine raw milk. To identify E. coli (ATCC 25922) contamination, the gene uspA was used, and PCR sensitivity and specificity were accessed by testing diluted samples ranging from 2 to 2.0 × 10(6) CFU/mL. To detect STEC, the stx1 and stx2 genes were selected as targets. After reaction standardization, the multiplex assay was tested in raw milk collected from 101 cows on dairy farms. PCR assay for E. coli detection had a specificity of 100% and sensitivity of 79% (P<0.0001), with a lower detection limit of 2 CFU/mL. Multiplex PCR assay had 100% sensitivity for E. coli positive raw milk samples, and 31.1% were contaminated with STEC, 28.3% of stx2, and 1.9% of stx1. The multiplex PCR assay described in the present study can be employed to identify and screen E. coli harboring stx1 and stx2 genes in raw milk on dairy farms and in industries.

Durante o processo de criopreservação de sêmen, os espermatozóides sofrem alguns danos que resultam na diminuição da fertilidade deste. O presente estudo foi realizado com o objetivo de avaliar os efeitos da utilização combinada de duas curvas de congelamento com dois diluentes comerciais (FR-5® e Botu-Crio®) sobre a criopreservação de sêmen eqüino. Foram analisados 20 ejaculados de dois garanhões. As amostras foram avaliadas por microscopia de contraste de fase e microscopia de epifluorescência, observando-se a motilidade progressiva e total do sêmen pós-descongelamento e a integridade e a funcionalidade da membrana dos espermatozóides. A combinação entre curva automatizada e Botu-Crio® apresentou as maiores médias nas análises de motilidade total e progressiva, após o descongelamento. O diluente Botu-Crio®, isoladamente, preservou também as membranas destes, quando foram realizadas as análises de integridade utilizando teste com diacetato de carboxifluoresceína e iodeto de propídio e funcionalidade de membrana pelo teste hiposmótico.

During semen cryopreservation, sperm cells were submitted to several deleterious events leading to membrane damage which result in fertility decrease. This study was designed to compare the effects of two freezing techniques (conventional and automated), and the use of two commercial extenders as cryoprotectants (FR-5® and Botu-Crio®) on total and progressive motility, integrity and functionality of spermatic membranes during the cryopreservation of equine semen. Twenty ejaculates from two stallions were analyzed. The total and progressive motility of fresh and post-thawing semen samples were evaluated by patterns assays. Function of plasmatic membrane was measured by the hipoosmotic swelling test. Integrity of plasmatic membrane was evaluated using carboxifluorescein diacatate and iodidium propide fluorescent probes. There were significant differences between the two freezing techniques and/or between cryoprotectants for all assessed parameters. The combination of Botu-Crio® and automated curves showed better results on total and progressive post-thawing motility. The extender Botu-Crio®, alone, showed to better preserve the membrane integrity and function.