Unravelling the bull fertility proteome

Abstract

In the last few decades a negative association between the level of milk production and fertility has been observed. Currently, the most utilized method of measuring male fertility employed by the livestock industry is related to the Non-Return Rate (NRR). Through differential proteome analysis, this study evaluated changes in the expression of the protein profile of spermatozoa collected from 16 bulls with different levels of field fertility expressed as an estimated relative conception rate (ERCR). The main aim is to identify putative protein markers to be used as putative indices of fertility. Two dimensional electrophoresis coupled with mass spectrometry analysis was used for protein separation and identification. To improve differential proteome analysis among experimental groups, a part of shotgun MS analysis was also performed. Three protein spots showed a differential expression pattern among all ERCR classes. Alpha enolase was significantly down-regulated in the ERCRÀ group, while two other proteins, isocitrate dehydrogenase and triosephosphate isomerase, were up-regulated in ERCRÀ in comparison to ERCR+. Alpha-enolase and isocitrate dehydrogenase subunit alpha (IDH-alpha) have been described in the literature for having a potential role in bull fertility. The possibility of determining protein biomarkers for fertility is more useful and less expensive than ERCR for acquiring rapid estimation of fertility because it does not require the use of field insemination trials. Shotgun MS analysis conducted on the same samples revealed 7 proteins down-regulated in the ERCRÀ group and 1 protein up-regulated. Among these proteins, calmodulin, ATP synthase mitochondrial subunits alpha and delta, malate dehydrogenase and sperm equatorial segment protein 1 were shown to be linked with sperm fertility.

Mechanisms of antibiotic resistance to enrofloxacin in uropathogenic Escherichia coli in dog

“…Shotgun analysis was performed as previously described in [25,26]. Briefly, protein extracts of six samples were precipitated with a cold mix of ethanol, methanol, and acetone (ratio 2:1:1, v/v), then dissolved in 6 M urea and 100 mM Tris at pH 7.5, and digested 50:1 (w⁄w) with sequence grade trypsin (Promega, Madison, WI, USA) at 37°C overnight after reduction with 10 mM DTT and alkylation with 20 mM IAA.…”

Changes in protein expression profiles in bovine endometrial epithelial cells exposed to E. coli LPS challenge

“…Label-free nanoflow liquid chromatography mass spectrometry (nLC-MS E ) was performed as previously described in [30][31][32] . Briefly, the protein extracts of nine biological samples (3 dosages LPS from cell culture from 3 cows) were precipitated with a cold mix of Ethanol, Methanol, and Acetone (ratio 2:1:1, v/v), then dissolved in 6 M Urea, 100 mM Tris pH 7.5 and digested 50:1 (w⁄w) with sequence grade trypsin (Promega, Madison, WI, USA) at 37°C overnight after reduction with 10 mM DTT and alkylation with 20 mM IAA.…”

Identification of Bovine Sperm Surface Proteins Involved in Carbohydrate-mediated Fertilization Interactions

“…By comparing these with those found with other glycoprobes, conclusions about specificity can be drawn. The complete list of proteins obtained in our proteomic study, organized from the Venn diagrams, is given in Tables I-III. Bovine Sperm Surface Lectinome-The 94 proteins identified by the CREDEX-MS approach were screened against a database that included all proteins (Ͼ4000) identified in 12 different proteomic analyses, covering either whole sperm (32)(33)(34)(35)(36) or fractions including isolated plasma membrane (37) or cytosolic matrix (17); or seminal plasma (38, 39) including epididymal (40,41) and accessory sex gland (42). To the best of our knowledge, more than 50% of these proteins are described herein for the first time (i.e.…”