New molecular variants of hypothalamus-pituitary-gonad axis genes and their association with early puberty phenotype in Bos taurus indicus (Nellore)

Endocrine system plays a major role in the control of reproductive functions which are regulated by the hypothalamus-pituitary-gonad axis and its interactions. FSH and LH receptor genes are expressed at the gonads and GnRH receptor gene is expressed at the anterior pituitary gland. Misense mutations of the FSH, LH or GnRH receptors, activating or inactivating their functions in mammals, are potentially useful to allow the understanding of the role of this group of gonadotropins in reproductive phenotypes as early puberty and birth interval length. In the present study, polymorphisms in bovine exon 11 and 3`UTR of LHR, exon 10 and 3`UTR of FSHR and GnRHR genes were characterized with some of them resulting in changes in the aminoacidic chain. These polymorphic sites were found in a Bos taurus indicus (Nellore) female population by means of PCR-SSCP and DNA sequencing. Association between nucleotidic/aminoacidic changes and early puberty were determined by Chi-square analysis. It was found association between FSHR 3`UTR polymorphisms at position 2181, 2248 and 2249 bp and early puberty phenotype (p < 0.05). The presence of these new molecular markers might be considered in further studies to validate its correlation with early puberty or other reproduction associated phenotypes in cattle breeds. (C) 2007 Published by Elsevier B.V.

Expression of alpha-synuclein is increased in the hippocampus of rats with high levels of innate anxiety

A genomic region neighboring the alpha-synuclein gene, on rat chromosome 4, has been associated with anxiety- and alcohol-related behaviors in different rat strains. In this study, we have investigated potential molecular and physiological links between alpha-synuclein and the behavioral differences observed between Lewis (LEW) and Spontaneously Hypertensive (SHR) inbred rats, a genetic model of anxiety. As expected, LEW rats appeared more fearful than SHR rats in three anxiety models: open field, elevated plus maze and light/dark box. Moreover, LEW rats displayed a higher preference for alcohol and consumed higher quantities of alcohol than SHR rats. alpha-Synuclein mRNA and protein concentrations were higher in the hippocampus, but not the hypothalamus of LEW rats. This result inversely correlated with differences in dopamine turnover in the hippocampus of LEW and SHR rats, supporting the hypothesis that alpha-synuclein is important in the downregulation of dopamine neurotransmission. A novel single nucleotide polymorphism was identified in the 30-untranslated region (3`-UTR) of the alpha-synuclein cDNA between these two rat strains. Plasmid constructs based on the LEW 3`-UTR sequence displayed increased expression of a reporter gene in transiently transfected PC12 cells, in accordance with in-vivo findings, suggesting that this nucleotide exchange might participate in the differential expression of alpha-synuclein between LEW and SHR rats. These results are consistent with a novel role for alpha-synuclein in modulating rat anxiety- like behaviors, possibly through dopaminergic mechanisms. Since the behavioral and genetic differences between these two strains are the product of independent evolutionary histories, the possibility that polymorphisms in the alpha-synuclein gene may be associated with vulnerability to anxiety- related disorders in humans requires further investigation. Molecular Psychiatry (2009) 14, 894-905; doi: 10.1038/mp.2008.43; published online 22 April 2008

Molecular characterization of Arabidopsis thaliana PUF proteins - binding specificity and target candidates

PUF proteins regulate both stability and translation through sequence-specific binding to the 3` UTR of target mRNA transcripts. Binding is mediated by a conserved PUF domain, which contains eight repeats of approximately 36 amino acids each. Found in all eukaryotes, they have been related to several developmental processes. Analysis of the 25 Arabidopsis Pumilio (APUM) proteins presenting PUF repeats reveals that 12 (APUM-1 to APUM-12) have a PUF domain with 50-75% similarity to the Drosophila PUF domain. Through three-hybrid assays, we show that APUM-1 to APUM-6 can bind specifically to the Nanos response element sequence recognized by Drosophila Pumilio. Using an Arabidopsis RNA library in a three-hybrid screening, we were able to identify an APUM-binding consensus sequence. Computational analysis allowed us to identify the APUM-binding element within the 3` UTR in many Arabidopsis transcripts, even in important mRNAs related to shoot stem cell maintenance. We demonstrate that APUM-1 to APUM-6 are able to bind specifically to APUM-binding elements in the 3` UTR of WUSCHEL, CLAVATA-1, PINHEAD/ZWILLE and FASCIATA-2 transcripts. The results obtained in the present study indicate that the APUM proteins may act as regulators in Arabidopsis through an evolutionarily conserved mechanism, which may open up a new approach for investigating mRNA regulation in plants.