System of KISS-KISS1R: focus on peripheral signaling in androgen-dependent tissues in the experimentally induced model hypogonadotropic hypogonadism.

Kisspeptins, ligands of G protein-coupled receptor 54 (GPR54) encoded by the KiSS-1 gene, have recently emerged as key gatekeepers of the gonadotropic axis. Unlike its role at the hypothalamus on GnRH secretion, the effects of kisspeptins on gonadal and other peripheral tissues need to be clarified. The purpose: To investigate the impact of experimentally induced hypogonadism in male rats on kisspeptins signaling in androgen-dependent tissues and blood. Methods: Wistar male rats (total number 31) were used. Rats were divided into four groups. Group 1 (control, prepubertal rats aged 2 months, n = 7). Group 2 (control, pubertal rats aged 4 months, n = 6). Group 3 (unilaterally gonadectomized (ULG) in neonatal period). Group 4 (ULG testosterone-treated with testosterone (T) propionate 5 mg/kg/d during 10 days). In all the four groups density of GPR54 in testes and muscle and serum kisspeptin levels and T levels were estimated. The data was expressed as median values (Me) that were compared by Wilkokson criterion. Results: Density of GPR54 in gonads in group 3 was lower than in group 2 (Me 0,88 ng/mg vs 1,13 ng/mg, p<0,05) and similar to group 1(Me 0,92 ng/mg). Unlike above, density of GPR54 in muscle in all groups 1,2,3 was not any differences (Me 0,1; 0,12; 0,13 ng/mg, p>0,05).Generally, density of GPR54 in group 2 in gonads was significantly higher than in the same group in muscle (Me 0,784 ng/mg vs 0.114 ng/mg, p<0,01). In the group 3 a significant decrease in serum levels of T (Me 15,39 ng/mg) in comparison with group 2 (Me 20,02 ng/mg, p<0,01) was invented. However, serum levels of kisspeptins in both groups had not any differences (0,27 ng/mg and 0,26 ng/mg, p>0,05). Treatment with testosterone propionate of the rats of group 4 lead to increase of serum level of T (from 15,39 ng/mg to 26,26 ng/mg, p<0,01), but didn`t modify the density of GPR54 in gonads (Me 0,79 ng/mg). Conclusions: Hypogonadism lead to decrease of kisspeptins signaling in peripheral androgen-dependent tissues. Serum level of kisspeptins is physiologically low and, probably, it can not be used as a marker of activity of kisspeptins system. Efficacy of treatment with testosterone is not enough that is required a novel therapeutic resources.

Characterization of baboon (Papio hamadryas) milk proteins.

The major proteins of baboon milk were identified as beta-lactoglobulin (beta LG), alpha-lactalbumin (alpha LA), lysozyme, lactoferrin, casein, and albumin by immobiline isoelectric focusing, SDS-PAGE, immunoblotting of gels with rabbit antisera to human alpha LA, lysozyme, and albumin and bovine beta LG and casein, and N-terminal sequencing of proteins blotted from gels. The first 30 N-terminal residues of baboon beta LG are identical to those of macaque (Macaca fasicularis) beta LG except for a (D/N) polymorphism at residue 2. The complete cDNA sequence and derived amino acid composition of beta LG were elucidated using RT-PCR amplification of poly(A)+ mRNA purified from lactating mammary gland. Baboon beta LG consists of 168 amino acid residues (M(r) 20,750) and is the longest beta LG identified to date. beta LG and alpha LA polymorphisms with three (A, B, and C) and two (A and B) variants, respectively, were detected by immobiline IEF, pH 4-6, of individual baboon milk samples at varying stages of lactation.

A strain-specific cyclin homolog in the fungal phytopathogen Colletotrichum gloeosporioides.

The fungus, Colletotrichum gloeosporioides, which infects the tropical pasture legume, Stylosanthes guianensis, contains highly variable mini-chromosomes. The transcription of strain-specific genomic DNA clones previously isolated from one variable mini-chromosome was investigated by using these clones to screen a cDNA library prepared from the fungus grown in liquid medium. A cDNA clone was obtained with one of the genomic clones and was sequenced. A single long open reading frame of 259 amino acids (aa) was detected with significant homology to cyclin proteins in other organisms. Northern blot analysis indicated that the cDNA corresponded to a low-abundance mRNA (approximately 0.001% of poly(A)+RNA). Southern blot analysis indicated that genes encoding this mRNA were discontinuously distributed in this fungal species, indicating it encodes a dispensable function. This result suggests that natural populations of fungi may have variable complements of cyclin-encoding genes.

DNA addition or deletion is associated with a major karyotype polymorphism in the fungal phytopathogen Colletotrichum gloeosporioides.

A 1.2 Mb minichromosome resolved by pulsed-field electrophoresis was present in two independent race 3 isolates of Colletotrichum gloeosporioides causing Type B anthracnose specifically on Stylosanthes guianensis cv. Graham in Australia. This chromosome was absent in duplicate isolates representing races 1, 2 and 4 which infect other S. guianensis cultivars. A gene library was prepared specifically from the 1.2 Mb minichromosome and ten independent DNA clones unique to this chromosome were identified by differential hybridisation to whole chromosome probes. All of the ten selected probes hybridised only to the 1.2 Mb minichromosome unique to the race 3 isolates but not to any chromosome in isolates of the other races. These ten probes also hybridised only to restriction-digested DNA of race 3 and were thus both chromosome- and strain-specific for Type B C. gloeosporioides. Hybridisation analysis of NotI fragments of the 1.2 Mb minichromosome with these sequences indicated that they were not tightly clustered on the chromosome. These data demonstrate that the variation in the occurrence of the 1.2 Mb minichromosome did not arise by rearrangement of the genome of a progenitor strain but involved either large scale deletion or addition of DNA. The 1.2 Mb minichromosome did not contain a cloned high-copy-number repeat sequence present on all other mini- and maxichromosomes, suggesting addition from a genetically distinct strain. All ten chromosome-specific DNA probes hybridised to a 2.0 Mb chromosome in all races of C. gloeosporioides causing Type A anthracnose on Stylosanthes spp. including S. guianensis.(ABSTRACT TRUNCATED AT 250 WORDS)