The sequence of a porcine cDNA encoding α-lactalbumin

A cDNA clone encoding porcine α-lactalbumin (αLA) was isolated and sequenced. The longest clone was 688 nucleotides (nt) long and encoded a preprotein of 141 amino acids (aa) including a leader peptide of 19 aa. The porcine cDNA exhibited a nt similarity of between 72.2%–83.5% to other αLA cDNAs and an aa similarity of between 50.8%–85.2% with other αLA aa sequences. The derived aa sequence varied at three positions from a previously reported sequence for porcine αLA obtained by direct aa sequencing.     

Cloning and analysing of 5‘ flanking region of Xenopus organizer gene noggin

Xenopus organizer specific gene noggin possesses nearly all the characterestic properties of the action of organizer to specify the embryonic body acis.To analyze how the maternal inherited factors control its expression pattern,we cloned the 5‘ regulatory region of noggin gene.The 1.5 kb upstream sequense could direct reporter gene to express in vivo and data from deletion analysis indicated that a 229 base pair fragmet is essential for activating noggin expression.We further demonstrated that the response elements within this regulatory region were indeed under the control of growth factor activin and Wnt signaling pathway components.     

Formaldehyde kills spores of Bacillus subtilis by DNA damage and small, acid-soluble spore proteins of the ααααααα/βββββββ-type protect spores against this DNA damage

Killing of wild-type spores of Bacillus subtilis with formaldehyde also caused significant mutagenesis; spores (termed α⁻β⁻) lacking the two major α/β-type small, acid-soluble spore proteins (SASP) were more sensitive to both formaldehyde killing and mutagenesis. A recA mutation sensitized both wild-type and α⁻β⁻ spores to formaldehyde treatment, which caused significant expression of a recA - lacZ fusion when the treated spores germinated. Formaldehyde also caused protein–DNA cross-linking in both wild-type and α⁻β⁻ spores. These results indicate that: (i) formaldehyde kills B. subtilis spores at least in part by DNA damage and (b) α/β-type SASP protect against spore killing by formaldehyde, presumably by protecting spore DNA.     

Characterization of sequence polymorphisms from microsatellite flanking regions in <Emphasis Type="Italic">Vitis</Emphasis> spp

Single nucleotide polymorphisms or SNPs are the most abundant form of genetic variation in the genome of plants and animals. Microsatellites are hypervariable regions of genome, while their flanking regions are assumed to be as conserved as the average of the genome. In the present study, flanking sequences of 10 microsatellite loci were compared in different cultivars of Vitis to determine the existing polymorphism. For every microsatellite, about 8 homozygous cultivars (regarding the microsatellite genotype) were chosen for sequencing. A total of 45 different varieties of Vitis and 91 sequences were analysed. Sequence polymorphisms were detected for all the microsatellite flanking regions studied, including single nucleotide polymorphisms (SNPs), insertions and deletions. The number of identified changes varied considerably among the loci with a frequency of one polymorphism every 41 nucleotides, being VVMD5 the most polymorphic one. A number of SNPs were used to design SNP markers, which were scored by dideoxy single base primer extension and capillary electrophoresis methodology. These SNP markers were employed to genotype 21 cultivars of Vitis vinifera and 4 varieties of other Vitis species. The utility of the markers developed as well as their utility for varietal identification and pedigree studies is discussed, using a similar study carried out with the 10 microsatellites as a reference.     

Complete nucleotide sequence of the chicken alpha A-crystallin gene and its 5' flanking region

The chicken alpha A-crystallin gene and 2.6 kb of its 5' flanking sequence have been isolated and characterized by electron microscopy and sequencing. The structural gene is 4.5 kb long and contains two introns, each approx. 1 kb in length. The first intron divides codons 63 and 64, and the second intron divides codons 104 and 105, as in rodents. There is little indication that the insert exon of rodents (an alternatively spliced sequence) is present in complete form in the chicken alpha A-crystallin gene; small stretches of similarity to this sequence were found throughout the gene. The 5' flanking sequence of the chicken alpha A-crystallin gene shows considerable sequence similarity with other mammalian alpha B-crystallin genes. In addition, one consensus sequence (GCAGCATGCCCTCCTAG) present in the 5' flanking region of the chicken alpha A-crystallin gene was found in the 5' flanking region of most reported crystallin genes.     

Genetic variation in skipjack tuna Katsuwonus pelamis(L.) using PCR‐RFLP analysis of the mitochondrial DNA D‐loop region

A high level of genetic diversity was observed in Katsuwonus pelamis populations from India ( h  = 0·952, ne  = 14·3) and Japan ( h  = 0·897, ne  = 8·9). The log‐likelihood ( G )‐based exact test revealed significant heterogeneity in the distribution of haplotypes between the two populations ( P  < 0·01, s . e . = 0·001). This result suggests that the two populations should now be treated as demographically independent and managed separately.     

Restriction fragment length polymorphisms for growth hormone, prolactin, osteonectin, α crystallin, γ crystallin, fibronectin and 21-steroid hydroxylase in cattle

Summary. Genomic DNAs from animals representing six breeds of cattle (Angus, Brahman, Hereford, Holstein, Jersey and Texas Longhorn) were screened with cloned gene probes in a search for restriction fragment length polymorphisms (RFLPs). Eleven RFLPs were identified using seven different probes: growth hormone, prolactin, osteonectin, α A-crystallin, γ crystallin, fibronectin and 21-steroid hydroxylase. The frequencies of the alleles identified by each probe were calculated and compared in a limited sampling of the six bovine breeds. These polymorphisms greatly enhance the pool of immunogenetic, biochemical and molecular markers available in cattle for linkage analysis, testing of parentage, and distinction of breeds.     

Analysis of genetic variation in the Belgian Blue Cattle breed using DNA sequence polymorphism at the growth hormone, low density lipoprotein receptor, α-subunit of glycoprotein hormones and thyroglobulin loci

Summary. New DNA sequence polymorphisms were identified at four bovine autosomal loci: growth hormone, low density lipoprotein receptor, α-subunit of glycoprotein hormones and thyroglobulin. Assuming independent assortment between these polymorphisms, the probabilities to be heterozygous at these four loci are 0.48, 0.36, 0.10 and 0.77 respectively, within the Belgian Blue Cattle breed (BBCB). Nucleotide diversity was estimated, showing that animals from the BBCB are heterozygous for 1/1450 nucleotides, a value significantly lower than the 1/500 value found in man. Moreover, we have estimated that the mutation rate at the cytosines of CG dinucleotides is about 10 times higher than that for other nucleotides.     

Restriction fragment length polymorphism of ovine casein genes: close linkage between the αs1-,αs2-,ß- and k-casein loci

Restriction fragment length polymorphism (RFLP) of ovine casein genes was investigated. Genomic DNA from 56 rams was digested with 10 restriction endonucleases and Southern blots probed with the four ovine casein cDNAs (alpha s1-, beta-, alpha s2- and kappa-Cn). Five enzymes, namely, BglI, PvuII, RsaI, TaqI and HindIII revealed nine different RFLPs. The inheritance of six of these polymorphisms was studied by segregation analysis of gametes in nine rams' families, and each of them could be related to the existence of alleles at the relevant casein locus. A close linkage between the four ovine casein genes was demonstrated since no recombination within the four pairs of loci examined, alpha s1-beta-Cn, alpha s1-kappa-Cn, beta-kappa-Cn and alpha s2-kappa-Cn, was observed in the progeny of double heterozygous rams. The casein genes are thus clustered in the ovine species as in the case of other mammals.     

鹅卵清蛋白基因5'端调控区的克隆和序列分析

通过PCR技术从产蛋鹅输卵管基因组中扩增出1．2kb的鹅清蛋白基因5’端调控区,将其亚克隆入phD18-T载体的多克隆位点(标记为pOV),经酶切和测序鉴定：扩增产物只有3个碱基发生了突变,其TATA框、组织特异性因子和卵清蛋白上游启动子均未发生变异,表明鹅清蛋白基因5’端调控区可作为启动外源基因表达的调控序列。为构建其启动外源基因的质粒表达载体奠定了研究基础。     

Immunohistochemical Localization of G Protein β1, β2, β3, β4, β5, and γ3 Subunits in the Adult Rat Brain

Abstract: The regional distributions of the G protein β subunits (Gβ1–β5) and of the Gγ3 subunit were examined by immunohistochemical methods in the adult rat brain. In general, the Gβ and Gγ3 subunits were widely distributed throughout the brain, with most regions containing several Gβ subunits within their neuronal networks. The olfactory bulb, neocortex, hippocampus, striatum, thalamus, cerebellum, and brainstem exhibited light to intense Gβ immunostaining. Negative immunostaining was observed in cortical layer I for Gβ1 and layer IV for Gβ4. The hippocampal dentate granular and CA1–CA3 pyramidal cells displayed little or no positive immunostaining for Gβ2 or Gβ4. No anti-Gβ4 immunostaining was observed in the pars compacta of the substantia nigra or in the cerebellar granule cell layer and Purkinje cells. Immunoreactivity for Gβ1 was absent from the cerebellar molecular layer, and Gβ2 was not detected in the Purkinje cells. No positive Gγ3 immunoreactivity was observed in the lateral habenula, lateral septal nucleus, or Purkinje cells. Double-fluorescence immunostaining with anti-Gγ3 antibody and individual anti-Gβ1–β5 antibodies displayed regional selectivity with Gβ1 (cortical layers V–VI) and Gβ2 (cortical layer I). In conclusion, despite the widespread overlapping distributions of Gβ1–β5 with Gγ3, specific dimeric associations in situ were observed within discrete brain regions.     

Analysis of the nucleotide sequence of the Mycoplasma hominis tuf gene and its flanking region

A gene from Mycoplasma hominis PG21 similar to the tuf gene encoding the elongation factor Tu (EF-Tu) of Escherichia coli was cloned and sequenced. The 1193-bp open reading frame flanked by a putative promoter and a potential stem-and-loop structure encoded a 44-kDa polypeptide. The tuf gene of M. hominis PG21 has the lowest G + C content seen in prokaryotes (38.2%). A gene (mhlmp1) encoding a variable surface exposed membrane protein (LMP1) was found downstream the 3' end of the tuf gene. It was found that the highly conserved tuf gene was linked to the highly variable mhlmp1 gene in 26 different M. hominis strains.     

Isolation of a new retrotransposon-like DNA sequence and its use in analysis of diversity within the Oryza officinalis

To better understand the genetic diversity of the wild relatives of rice (Oryza sativa L.) in the O. officinalis species complex repetitive DNA markers were obtained from the diploid species of this complex. One cloned sequence from O. eichingeri gave intense hybridization signals with all species of the O. officinalis complex. This 242 bp clone, named pOe.49, has a copy number from 0.9 to 4.0 × 10⁴ in diploid species of this complex. Analysis of the primary structure and database searches revealed homology of pOe.49 to a number of sequences representing part of the integrase coding domain of retroviruses and gypsy-like retrotransposons. Sequencing of specific PCR products confirmed that pOe.49 is part of a gypsy-like retrotransposon. RFLP analysis was used to study the genomic organisation of pOe.49 among 30 accessions of the O. officinalis complex using 10 restriction enzymes. Diversity analysis based on 120 polymorphic fragments obtained from the RFLP assay grouped the O. officinalis complex accessions by genome, species and eco-geographic groups. The results suggest that, with further characterization, this retrotransposon-like DNA sequence may be useful for phylogenetic analysis of species in the O. officinalis complex. This revised version was published online in August 2006 with corrections to the Cover Date.