Protein kinase C activity in boar sperm.

Male germ cells undergo different processes within the female reproductive tract to successfully fertilize the oocyte. These processes are triggered by different extracellular stimuli leading to activation of protein phosphorylation. Protein kinase C (PKC) is a key regulatory enzyme in signal transduction mechanisms involved in many cellular processes. Studies in boar sperm demonstrated a role for PKC in the intracellular signaling involved in motility and cellular volume regulation. Experiments using phorbol 12-myristate 13-acetate (PMA) showed increases in the Serine/Threonine phosphorylation of substrates downstream of PKC in boar sperm. In order to gain knowledge about those cellular processes regulated by PKC, we evaluate the effects of PMA on boar sperm motility, lipid organization of plasma membrane, integrity of acrosome membrane and sperm agglutination. Also, we investigate the crosstalk between PKA and PKC intracellular pathways in spermatozoa from this species. The results presented here reveal a participation of PKC in sperm motility regulation and membrane fluidity changes, which is probably associated to acrosome reaction and to agglutination. Also, we show the existence of a hierarchy in the kinases pathway. Previous works on boar sperm suggest a pathway in which PKA is positioned upstream to PKC and this new results support such model.

Cervical mucus characteristics and hormonal status at insemination of Holstein cows.

The present study was carried out to characterize the cervical mucus (CM) collected when inseminating Holstein cows and to relate the secretion pattern with pregnancy. The mucus was collected from mid-cervix of 64 cows with spontaneus estrus (SE) and induced estrus (IE). The quantity, pattern and consistency of the mucus, pH, arborization patterns and the sperm motility were observed. The levels of progesterone and estradiol 17ß in serum were also determined. Pregnancy detection was performed by means of transrectal ultrasonography 60 days after insemination. Mucous secretion of cows with SE was significantly different from those with IE, showing a lower degree of crystallization (SE 2.00; IE 2.75) and a lower level of steroid hormones (P4: SE 0.17 ng/ml and IE 0.33 ng/ml (t 1.99547 α 0.05); E2: SE 30.95 pg/ml and IE 47.76 pg/ml (t 1.99495 α 0.05). Progesterone level was significantly lower and estrogen significantly higher in pregnant cows (P) in relation to that observed in non pregnant females (N) (P4: P 0.20 ng/ml and N 0.44 ng/ml (t 1.99602 α 0.05); E2: P 54.77 pg/ml and N 40.75 pg/ml (t 1.99505 α 0.05). In conclusion pregnancy was associated with acopious, clear and watery discharge (similar to egg white), with an arborization degree of 2.25, presence of atypical fern leaves together with rosette formations and needles or thorns on rails due to low levels of progesterone accompanied by high concentrations of estrogens.

First evidence of the interaction between deleted in malignant brain tumor 1 and galectin-3 in the mammalian oviduct.

The oviduct supports the transport and final maturation of gametes, and harbors fertilization and early embryo development. The oviductal epithelium is responsible for providing the correct environment for these processes. Deleted in malignant brain tumor 1 (DMBT1) is expressed by multiple organisms and several cell types, and the interaction of the rabbit ortholog of DMBT1 with galectin-3 (gal-3) modulates the polarity of epithelial cells. This interaction has not yet been shown in locations other than rabbit kidney and human-cultured endothelial cells. DMBT1 and gal-3 also protect epithelial layers from pathogens and trauma, and are innate immunity components. DMBT1 has been detected in the porcine oviduct, and gal-3 has been reported in the Fallopian tube and in the cow oviduct. Interaction between both proteins would show a probable physiological function in the female reproductive tract. This work describes the presence and co-localization of DMBT1 and gal-3 mainly in the apical region of the epithelial cells of the Fallopian tube and the porcine oviduct, and co-immunoprecipitation in membrane-enriched epithelial cell extracts from the porcine oviduct. The findings strongly support a functional interaction in the mammalian oviduct, suggestive of a role on epithelial protection and homeostasis, which might be related to epithelium-gamete interaction.

S100A7 is present in human sperm and a homologous pig sperm protein interacts with sperm-binding glycoprotein (SBG).

In sows, the oviductal sperm-binding glycoprotein (SBG), which binds to the periacrosomal region of boar sperm, has been shown to be involved in sperm selection. In this work, we isolated porcine sperm proteins that interact with SBG. One of them is identified as a homologue of human S100A7 (psoriasin). Anti-human S100A7 antibodies show that this homologous protein localises to the head of sperm. The isolation of a homologue of S100A7 based on affinity to SBG and its localisation at the head of sperm leads us to suggest that S100A7's homologous protein may be involved in the negative selection of sperm by SBG in pigs. Human S100A7 shows antibacterial properties, particularly over Escherichia coli, a species that has demonstrated deleterious effects on human sperm. We searched for S100A7 in human sperm and found that it is present and localises at the acrosomal region. Thus, we report the presence of S100A7 in human sperm and of a homologous protein in pig, with similar localisations. In humans, an antimicrobial role seems likely for psoriasin; in porcine sperm the studied protein binds to SBG suggesting a function in sperm selection, but an antimicrobial function cannot be ruled out.

ATP13A2 missense mutations in juvenile parkinsonism and young onset Parkinson disease.

OBJECTIVE: To assess the prevalence, nature, and associated phenotypes of ATP13A2 gene mutations among patients with juvenile parkinsonism (onset <21 years) or young onset (between 21 and 40 years) Parkinson disease (YOPD). METHODS: We studied 46 patients, mostly from Italy or Brazil, including 11 with juvenile parkinsonism and 35 with YOPD. Thirty-three cases were sporadic and 13 had positive family history compatible with autosomal recessive inheritance. Forty-two had only parkinsonian signs, while four (all juvenile-onset) had multisystemic involvement. The whole ATP13A2 coding region (29 exons) and exon-intron boundaries were sequenced from genomic DNA. RESULTS: A novel homozygous missense mutation (Gly504Arg) was identified in one sporadic case from Brazil with juvenile parkinsonism. This patient had symptoms onset at age 12, levodopa-responsive severe akinetic-rigid parkinsonism, levodopa-induced motor fluctuations and dyskinesias, severe visual hallucinations, and supranuclear vertical gaze paresis, but no pyramidal deficit nor dementia. Brain CT scan showed moderate diffuse atrophy. Furthermore, two Italian cases with YOPD without atypical features carried a novel missense mutation (Thr12Met, Gly533Arg) in single heterozygous state. CONCLUSIONS: We confirm that ATP13A2 homozygous mutations are associated with human parkinsonism, and expand the associated genotypic and clinical spectrum, by describing a homozygous missense mutation in this gene in a patient with a phenotype milder than that initially associated with ATP13A2 mutations (Kufor-Rakeb syndrome). Our data also suggest that ATP13A2 single heterozygous mutations might be etiologically relevant for patients with YOPD and further studies of this gene in Parkinson disease are warranted.

Growth-rate regulation of the Bacillus subtilis accBC operon encoding subunits of acetyl-CoA carboxylase, the first enzyme of fatty acid synthesis.

Acetyl-CoA carboxylase catalyses the synthesis of malonyl-CoA, the first intermediate in fatty acid (hence phospholipid) synthesis. The accBC operon from Bacillus subtilis codes for two subunits of acetyl-CoA carboxylase, biotin carboxyl-carrier and biotin carboxylase. In this work, the 5'-end of the accBC mRNA was determined by primer-extension, and transcriptional fusion analysis of the accBC promoter was carried out under a variety of growth conditions. A direct correlation between the levels of transcription of the accBC genes and the rate of cellular growth is reported. Consistent results were also obtained in nutritional upshift and downshift experiments.

The genes encoding the biotin carboxyl carrier protein and biotin carboxylase subunits of Bacillus subtilis acetyl coenzyme A carboxylase, the first enzyme of fatty acid synthesis.

The genes encoding two subunits of acetyl coenzyme A carboxylase, biotin carboxyl carrier protein, and biotin carboxylase have been cloned from Bacillus subtilis. DNA sequencing and RNA blot hybridization studies indicated that the B. subtilis accB homolog which encodes biotin carboxyl carrier protein, is part of an operon that includes accC, the gene encoding the biotin carboxylase subunit of acetyl coenzyme A carboxylase.

Transposon-mediated amikacin resistance in Klebsiella pneumoniae.

A multiresistant Klebsiella pneumoniae strain isolated from neonates in Mendoza, Argentina, harbored a 48-kilobase-pair (kbp) plasmid, pMET1, with genetic determinants for resistance to amikacin and also ampicillin, kanamycin, streptomycin, and tobramycin. This plasmid was compared with pJHCMW1, a previously isolated 11-kbp plasmid carrying transposon Tn1331, which encodes resistance to amikacin, as well as ampicillin, kanamycin, streptomycin, and tobramycin, and which was originally present in a K. pneumoniae strain that caused an outbreak in a hospital in Buenos Aires, Argentina. The comparison demonstrated that the replication regions of the two plasmids are unrelated. However, in pMET1 an 11-kbp transposition element, Tn1331.2, was identified; it was closely related to Tn1331, with the difference that a 3-kbp BamHI DNA fragment carrying the aminoglycoside resistance genes was duplicated in tandem.