Effect of depletion tests (DT) on the composition of boar semen.

We conducted two depletion tests during the summer (DT 1) and winter (DT 2) to study their effect on selected biochemical parameters of boar semen. We subjected three boars to DT for 10 consecutive days. The first 3 days (Period 1) of ejaculate collections represented the reserves of the extragonadal spermatozoa and accessory sex gland secretions, whereas the other seven days (Period 2) represented the daily spermatozoa output and the secretory capacity of the accessory sex glands. We observed noticeable changes in the quantity and quality of the semen in DT 1 and 2. There was an increase in the number of spermatozoa with morphological defects, particularly coiled tails and detached acrosomes. The secretory activity of the accessory sex glands, particularly the vesicular glands, was slightly influenced by season. Depletion tests caused disturbances in the qualitative relations of secretions of the accessory sex glands, which were related to changes in the sperm plasmalemma integrity. These tests can be used to determine the total spermatozoa output, and to assess the secretory capacity of the accessory sex glands of boars.

Cloning of complementary DNA encoding the pB1 component of the 54-kilodalton glycoprotein of boar seminal plasma.

Complementary DNA (cDNA) encoding a protein component pB1 (also pAIF-1 and DQH) of the 54-kilodalton glycoprotein of boar seminal plasma was cloned and its nucleotide sequence was determined (Gene Bank accession no. AF047026). The pB1 precursor protein is a 130-amino-acid-long polypeptide containing a 25-amino-acid-long signal peptide. The amino acid sequence of the pB1 is homologous to that of SFP1_BOVIN (named also BSP-A1/A2, PDC-109/ major protein and SVSp109), SFP3_BOVIN (BSP-A3), SFP4 BOVIN (BSP-30 KD), and SP1_HORSE (HSP-1) seminal plasma proteins. The homology extends also for the signal peptide of SFP1_BOVIN protein. All these seminal plasma proteins contain two fibronectin type-II domains that differ from those found in other proteins such as colagenases, fibronectins, and mannose receptors. The first domain located in the N-terminal region of pB1 is four amino acids shorter than those present in other proteins. High homology is also observed between 3' noncoding regions of the nucleotide sequences of cDNAs of pB1_PIG and SFP1_BOVIN (Gene Bank accession nos. AF047026 and P02784, respectively).

Heparin- and Zn2+-binding proteins from boar seminal plasma.

Low molecular mass, heparin-binding proteins from seminal plasma play an important role in gametes interaction whereas plasmatic Zn2+-binding proteins stabilize chromatin and plasmalemma structures and protect spermatozoa in the female reproductive tract. By means of affinity chromatography the heparin- and Zn2+-binding proteins were isolated from boar seminal plasma and both preparations were analyzed by reverse HPLC. Most of the proteins bound to heparine and Zn2+-ions were classified as spermadhesins. Three fractions binding exclusively Zn2+ were isolated. They differ in amino-acid composition, content of glucosamine and content of protein components revealed by SDS/PAGE.

Biochemical properties and usefulness of boar semen for liquid preservation following atropine administration.

Four sexually mature boars were used in two different experiments. In Experiment I, two boars were injected once subcutaneously with atropine and, ejaculates were collected after 30, 60 and 90 min. In Experiment II, each boar was injected weekly with 25, 37.5 and 50 mg of atropine, and ejaculates were collected after 30 min. Ejaculates obtained in Exp. II were diluted with Kortowo-3 extender (Olsztyn, Poland), with and without the addition of low density lipoprotein fraction (LDF) isolated from hen egg yolk,and stored at 5 degrees C and 16 degrees C for 5-6 days. Atropine caused a decrease in semen volume and an increase in sperm concentration with fewer agglutinated spermatozoa. Changes in sperm motility were not significant. There was a significant increase in the content of fructose, zinc, citric acid and protein in the seminal plasma of atropine-injected boars. Furthermore, increased antiproteolytic and antiperoxidant activity as well as seminal phosphatases were also observed. No significant changes were observed in the content of free sialic acid, whereas bound sialic acid was significantly increased in Exp. II. A decrease in osmolality and pH of seminal plasma was observed. Electrophoretic studies revealed that there were alterations in the molecular forms of seminal phosphatases and proteinase inhibitors. There were no significant changes in the percentage of morphologically abnormal spermatozoa, osmotic plasmalemma resistance at the acrosomal region (ORT) and malondialdehyde production in the spermatozoa. AspAT activity recovered from cold shocked spermatozoa was significantly reduced, whereas disturbances in plasma membrane permeability to fluorochrome HO 258 were observed in Exp. I. Semen of atropine-injected boars had increased sperm viability during liquid preservation at 5 and 16 degrees C.