Bos taurus ultralong CDR H3 antibodies.

Cow antibodies are unusual in having an exceptionally long third complementarity determining region of the heavy chain (CDR H3). These CDR H3s have a multitude of cysteines and form a distinct domain characterized by a β-ribbon 'stalk' and disulfide bonded 'knob'. Cows appear to utilize somatic hypermutation of a single VDJ rearrangement to produce an astounding variety of distinct CDR H3 sequences with different disulfide bonding patterns within the knob.

From PAWP to "Pop": opening up new pathways to fatherhood.

Infertility remains a significant problem for many couples. Approximately one in seven couples who attempt to conceive will fail to do so within 1 year. In about 65% of these cases, there is a male component of infertility.

Mitochondrial fusion protein MFN2 interacts with the mitostatin-related protein MNS1 required for mouse sperm flagellar structure and function.

Background: Cilia and the sperm flagellum share many structural properties. Meiosis-specific nuclear structural 1 (MNS1) is a recently characterized protein that is abundantly expressed in post-meiotic spermatids and is required for proper flagellar and motile cilia formation. To explore the possible functions of MNS1, we performed a BLAST search and determined it is homologous to the conserved domain pfam13868, exemplified by mitostatin.

Adenine nucleotide metabolism and a role for AMP in modulating flagellar waveforms in mouse sperm.

While most ATP, the main energy source driving sperm motility, is derived from glycolysis and oxidative phosphorylation, the metabolic demands of the cell require the efficient use of power stored in high-energy phosphate bonds. In times of high energy consumption, adenylate kinase (AK) scavenges one ATP molecule by transphosphorylation of two molecules of ADP, simultaneously yielding one molecule of AMP as a by-product. Either ATP or ADP supported motility of detergent-modeled cauda epididymal mouse sperm, indicating that flagellar AKs are functional.

Signaling in sperm: toward a molecular understanding of the acquisition of sperm motility in the mouse epididymis.

Sperm motility encompasses a wide range of events involving epididymal maturation and activation of biochemical pathways, most notably cyclic AMP (cAMP)-protein kinase A (PKA) activation. Following the discovery of guanine-nucleotide exchange factors (RAPGEFs), also known as exchange proteins activated by cAMP, we investigated the separate roles of PKA and RAPGEFs in sperm motility. RT-PCR showed the presence of Rapgef3, Rapgef4, and Rapgef5, as well as several known RAPGEF partner mRNAs, in spermatogenic cells.

Male mice express spermatogenic cell-specific triosephosphate isomerase isozymes.

Triosephosphate isomerase 1 (TPI1) is a member of the glycolytic pathway, which is a critical source of energy for motility in mouse sperm. By immunoblotting, we detected two male, germ line-specific TPI1 bands (Mr 33,400 and 30,800) as well as the somatic-type band (Mr 27,700). Although all three bands were observed in spermatogenic cells, somatic-type TPI1 disappeared from sperm during epididymal maturation.

Characterization of capacitation, cryoinjury, and the role of seminal plasma in porcine sperm.

Capacitation is a biochemical pathway sperm must undergo to be able to fertilize an oocyte, whereas cryoinjury is cryopreservation-induced biophysical damage which renders sperm immediately capable of fertilization. Similarities between capacitation and cryoinjury have not been fully elucidated. The present study attempted to characterize both processes, including the role of seminal plasma (SP).

Seminal plasma proteins inhibit in vitro- and cooling-induced capacitation in boar spermatozoa.

Dilute boar seminal plasma (SP) has been shown to inhibit in vitro capacitation and cooling-induced capacitation-like changes in boar spermatozoa, as assessed by the ability of the spermatozoa to undergo an ionophore-induced acrosome reaction. We hypothesised that the protein component of SP is responsible for this effect. To test this hypothesis, varying concentrations of total SP protein or SP proteins fractionated by heparin binding were assayed for their ability to inhibit in vitro capacitation, as well as cooling- and cryopreservation-induced capacitation-like changes.

Molecular cloning and expression of the CRISP family of proteins in the boar.

The family of mammalian cysteine-rich secretory proteins (CRISP) have been well characterized in the rat, mouse, and human. Here we report the molecular cloning and expression analysis of CRISP1, CRISP2, and CRISP3 in the boar. A partial sequence published in the National Center for Biotechnology Information (NCBI) database was used to derive the full-length sequences for CRISP1 and CRISP2 using rapid amplification of cDNA ends.

Current concepts of molecular events during bovine and porcine spermatozoa capacitation.

Spermatozoa are required to undergo the processes of capacitation before they obtain fertilizing ability. The molecular changes of capacitation are still not fully understood. However, it is accepted that capacitation is a sequential process involving numerous physiological changes including destabilization of the plasma membrane, alterations of intracellular ion concentrations and membrane potential, and protein phosphorylation.

Effects of seminal plasma on cooling-induced capacitative changes in boar sperm.

Porcine seminal plasma (SP) has been shown to contain factors that have a decapacitative or capacitation-inhibiting effect on sperm. The objectives of the present study were to compare the capacitative changes observed in cooled sperm with those seen in sperm after in vitro capacitation and to determine whether SP could prevent these changes. Sperm were subjected to incubation or to slow cooling under noncapacitating or capacitating conditions.

Effects of extender, incubation temperature, and added seminal plasma on capacitation of cryopreserved, thawed boar sperm as determined by chlortetracycline staining.

The effect on apparent capacitation status of frozen-thawed (FT), washed boar sperm was examined in capacitation-supporting medium at 39 degrees C without added seminal plasma (SP) or supplemented with either 10 or 20% (v/v) boar SP. The thawed sperm from three boars were washed to remove the egg yolk-based freezing medium (EY) and then incubated for 1-8h after addition of SP. Capacitation status of the sperm was determined microscopically using chlortetracycline staining patterns.

Effect of cooling and seminal plasma on the capacitation status of fresh boar sperm as determined using chlortetracycline assay.

Insemination of sows with frozen-thawed spermatozoa results in lower fertility, in part due to spermatozoa having undergone a capacitation-like reaction. The present study employed chlortetracycline (CTC) staining analysis to investigate the effect of adding 20% (v/v) boar seminal plasma (SP) to boar spermatozoa on the temporal progress of capacitation and the acrosome reaction in spermatozoa cooled to 5 degrees C or incubated at 39 degrees C. Based on CTC staining patterns, seminal plasma appeared to reverse capacitation in spermatozoa that had undergone capacitation while incubated at 39 degrees C in a capacitation-supporting medium from 59.