Secretagogin in the brain and pituitary of the catfish, Clarias batrachus: Molecular characterization and regulation by insulin.

Secretagogin (scgn), is a novel hexa EF-hand, phylogenetically conserved calcium-binding protein. It serves as Ca2+ sensor and participates in Ca2+ -signaling and neuroendocrine regulation in mammals. However, its relevance in the brain of non-mammalian vertebrates has largely remained unexplored. To address this issue, we studied the cDNA encoding scgn, scgn mRNA expression, and distribution of scgn-equipped elements in the brain and pituitary of a teleost, Clarias batrachus (cb). The cbscgn cDNA consists of three transcripts (T) variants: T1 (2185 bp), T2 (2151 bp) and T3 (2060 bp). While 816 bp ORF in T1 and T2 encodes highly conserved six EF-hand 272 aa protein fully capable of Ca2+ -binding, 726-bp ORF in T3 encodes 242 aa protein. The T1 showed >90% and >70% identity with scgn of catfishes, and other teleosts and mammals, respectively. The T1-mRNA was widely expressed in the brain and pituitary, while the expression of T3 was restricted to the telencephalon. Application of the anti-scgn antiserum revealed a ∼32 kDa scgn-immunoreactive (scgn-i) band (known molecular weight of scgn) in the forebrain tissue, and immunohistochemically labeled neurons in the olfactory epithelium and bulb, telencephalon, preoptic area, hypothalamus, thalamus, and hindbrain. In the pituitary, scgn-i cells were seen in the pars distalis and intermedia. Insulin is reported to regulate scgn mRNA in the mammalian hippocampus, and feeding-related neuropeptides in the telencephalon of teleost. Intracranial injection of insulin significantly increased T1-mRNA expression and scgn-immunoreactivity in the telencephalon. We suggest that scgn may be an important player in the regulation of olfactory, neuroendocrine system, and energy balance functions in C. batrachus.

Reinvestigating the status of malaria parasite (Plasmodium sp.) in Indian non-human primates.

Many human parasites and pathogens have closely related counterparts among non-human primates. For example, non-human primates harbour several species of malaria causing parasites of the genus Plasmodium. Studies suggest that for a better understanding of the origin and evolution of human malaria parasites it is important to know the diversity and evolutionary relationships of these parasites in non-human primates. Much work has been undertaken on malaria parasites in wild great Apes of Africa as well as wild monkeys of Southeast Asia however studies are lacking from South Asia, particularly India. India is one of the major malaria prone regions in the world and exhibits high primate diversity which in turn provides ideal setting for both zoonoses and anthropozoonoses. In this study we report the molecular data for malaria parasites from wild populations of Indian non-human primates. We surveyed 349 fecal samples from five different Indian non-human primates, while 94 blood and tissue samples from one of the Indian non-human primate species (Macaca radiata) and one blood sample from M. mulatta. Our results confirm the presence of P. fragile, P. inui and P. cynomolgi in Macaca radiata. Additionally, we report for the first time the presence of human malarial parasite, P. falciparum, in M. mulatta and M. radiata. Additionally, our results indicate that M. radiata does not exhibit population structure probably due to human mediated translocation of problem monkeys. Human mediated transport of macaques adds an additional level of complexity to tacking malaria in human. This issue has implications for both the spread of primate as well as human specific malarias.

Mycobacterium tuberculosis in Wild Asian Elephants, Southern India.

We tested 3 ild Asian elephants (Elephas maximus) in southern India and confirmed infection in 3 animals with Mycobacterium tuberculosis, an obligate human pathogen, by PCR and genetic sequencing. Our results indicate that tuberculosis may be spilling over from humans (reverse zoonosis) and emerging in wild elephants.

The alpaca melanocortin 1 receptor: gene mutations, transcripts, and relative levels of expression in ventral skin biopsies.

The objectives of the present study were to characterize the MC1R gene, its transcripts and the single nucleotide polymorphisms (SNPs) associated with coat color in alpaca. Full length cDNA amplification revealed the presence of two transcripts, named as F1 and F2, differing only in the length of their 5'-terminal untranslated region (UTR) sequences and presenting a color specific expression. Whereas the F1 transcript was common to white and colored (black and brown) alpaca phenotypes, the shorter F2 transcript was specific to white alpaca. Further sequencing of the MC1R gene in white and colored alpaca identified a total of twelve SNPs; among those nine (four silent mutations (c.126C>A, c.354T>C, c.618G>A, and c.933G>A); five missense mutations (c.82A>G, c.92C>T, c.259A>G, c.376A>G, and c.901C>T)) were observed in coding region and three in the 3'UTR. A 4 bp deletion (c.224 227del) was also identified in the coding region. Molecular segregation analysis uncovered that the combinatory mutations in the MC1R locus could cause eumelanin and pheomelanin synthesis in alpaca. Overall, our data refine what is known about the MC1R gene and provides additional information on its role in alpaca pigmentation.

The alpaca agouti gene: genomic locus, transcripts and causative mutations of eumelanic and pheomelanic coat color.

The agouti gene encodes the agouti signaling protein (ASIP) which regulates pheomelanin and eumelanin synthesis in mammals. To investigate the role of agouti in coat color variation of alpaca, we characterized the agouti gene and identified three mutations potentially involved with the determinism of eumelanic and pheomelanic phenotypes. The exon-4 hosts the mutations g.3836C>T, g.3896G>A and g.3866_3923del57. Further analysis of these mutations revealed two genotypes for black animals. The reverse transcription analysis of mRNA purified from skin biopsies of alpaca revealed the presence of three transcripts with different 5' untranslated regions (UTRs) and color specific expression. The white specific transcript, possibly originating from a duplication event (intra-chromosomal recombination) of the agouti gene is characterise by a 5'UTR containing 142bp of the NCOA6 gene sequence. Furthermore, the relative level expression analysis of mRNA demonstrates that the agouti gene has up-regulated expression in white skin, suggesting a pleiotropic effect of agouti in the white phenotype. Our findings refine the structure of the agouti locus and transcripts and provide additional information in order to understand the role of agouti in the pigmentation of alpaca.