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Biochemical Genetics (v.35, #7-8)
Organization, Sequence, and Expression of the Gene Encoding IGFII from Barramundi (Teleosteii; Lates calcarifer) by Chris Collet; Judith Candy; Neil Richardson; Vicki Sara (pp. 211-224).
We have characterized the gene encoding IGFII from the teleost fish species barramundi, Lates calcarifer. The barramundi gene spans 5.5 kb of DNA and comprises four exons and three introns. The barramundi and salmon IGFII genes share >85% sequence similarity across all the exons and also share some regions of high sequence identity within the promoter regions and the introns. The mature barramundi IGFII peptide comprises 70 amino acid residues and shares 84 and 96% similarity with salmonid and seabream IGFII, respectively, with the majority of replacements located in regions cleaved from the mature peptide. IGFII mRNA transcripts were detected in liver, muscle, intestine, gill, heart, and brain from juvenile barramundi. This distribution mirrors that seen in the rainbow trout and seabream and extends the tissue types which synthesize IGFII in fish to include the intestine.
Keywords: IGFII; teleost; barramundi; gene structure
Polymorphism of Mitochondrial DNAs of Yunnan Domestic Water Buffaloes, Bubalus bubalis, in China, Based on Restriction Endonuclease Cleavage Patterns by Wenping Hu; Baoming Xu; Linsheng Lian (pp. 225-231).
Restriction endonuclease cleavage patterns of mitochondrial DNA(mtDNA) of three local types of Yunnan native water buffalo were analyzed using 18 enzymes which recognize six nucleotides. Among the 12 animals analyzed, 3 of 18 enzymes, BamHI, EcoRI, and ScaI, revealed polymorphisms. Three mtDNA types were identified. The results indicate that a relatively low level of mtDNA variation exists in Yunnan domestic water buffaloes. The origin of Chinese buffalo derived from Yunnan province of China is discussed.
Keywords: Yunnan water buffalo; mitochondrial DNA; restriction endonuclease
Allozyme Polymorphisms and Biochemical-Genetic Taxon Markers in Lampreys (Lampetra, Eudontomyzon, Petromyzon) by Ralf Engelhorn; Arnd Schreiber (pp. 233-249).
Variation at 23 putative enzyme-coding loci was scored in 424 lampreys, including 321 European brook lampreys (Lampetra planeri), 83 European river lampreys (L. fluviatilis), 11 Ukrainian brook lampreys (Eudontomyzon mariae), and nine sea lampreys (Petromyzon marinus). Twelve polymorphisms are described for Lampetra species (LDH*, SOD-2*, PNP*, AAT-1*, AK-1*, ES-2*, LGL*, MPI*, GPI-1*, GPI-2*, PGM*, IDHP-2*), and two each for E. mariae (GPI-1*, ME-2*) and P. marinus (MDH-1*, ME-2*). Diagnostic allozymes are presented for the discrimination of lamprey taxa, some of which are difficult to recognize from the morphology of ammocoetes larvae, the life stage usually encountered when collecting cyclostomes. The allelic markers described permit the clear allocation to a genus, except for the species L. fluviatilis and L. planeri, which are not differentiated by qualitative allozyme analysis.
Keywords: allozyme polymorphism; species markers; population genetics; Cyclostomata; Petromyzontidae
Characterization of the EstP Protein in Drosophila melanogaster and Its Conservation in Drosophilids by Mira M. Dumancic; John G. Oakeshott; Robyn J. Russell; Marion J. Healy (pp. 251-271).
The β-esterase cluster of D. melanogaster comprises two tandemly duplicated genes. Est6 encodes the well-characterized 5′ gene, but the product of the second gene, denoted EstP, had not previously been identified. Here we show that the EstP gene encodes the carboxylesterase EST7. Expression of EstP using the Baculovirus system led to production of a carboxylesterase biochemically indistinguishable from EST7. Furthermore, a naturally occurring EstP variant produces greatly reduced amounts of EstP mRNA and no detectable EST7 protein. Finally, introduction of a wild-type copy of EstP by germline transformation into the variant strain confers the wild-type EST7 phenotype. We show that EST7 differs from EST6 in its substrate and inhibitor specificities and tissue distribution. Germline transformation experiments show that EstP expression is controlled by sequences located between 192 bp 5′ and 609 bp 3′ of the EstP coding region. Data comparisons with other drosophilid esterases suggest that the site of expression, and hence the function, of EST7 has been conserved across lineages in both the subgenera Drosophila and Sophophora.
Keywords: EstP ; EST7; gene duplication; gene regulation; carboxylesterase
Trinucleotide Microsatellite Loci and Increased Heterozygosity in Cross-Species Applications in the Social Wasp, Polistes by Joan E. Strassmann; John M. Peters; Karen Barefield; Carlos R. Solís; Colin R. Hughes; David C. Queller (pp. 273-279).
Though microsatellite loci are usually found to be most polymorphic in the species in which they are first identified, we have found significant increases in polymorphisms in some cross-species applications. We present eight new trinucleotide microsatellite loci derived from two species of social wasps, Polistes annularis and Polistes bellicosus. We assessed the primers designed from these species and the degree of polymorphism in two additional species, P. dorsalis, which is very closely related to P. bellicosus, and P. dominulus, which is an Old World congener, thought to have diverged from New World Polistes over 80 million years ago. Cross-species applications for these microsatellite loci indicate that the priming sites from P. bellicosus loci are conserved in P. dorsalis and amplified similarly sized products with higher heterozygosities than the original species in two of three cases. A locus that was monomorphic in P. annularis had a heterozygosity of 1.0 in the distantly related P. dominulus. Cross-species applications of these loci indicated that alleles were generally of similar lengths in the new and original species when they retained their heterozygosity.
Keywords: microsatellites; trinucleotide repeats; Vespidae; heterozygosity
Microsatellites in the Sand Lizard (Lacerta agilis): Description, Variation, Inheritance, and Applicability by Annica Gullberg; Håkan Tegelström; Mats Olsson (pp. 281-295).
We developed microsatellite markers for the sand lizard (Lacerta agilis) to enable investigations of the genetic variability within and among populations with a heterogeneous spatial distribution in Sweden. The populations, which could not be characterized by variation in allozymes or mitochondrial DNA, had a substantial level of variability in microsatellite loci. However, the variability in Swedish populations was limited compared to a large, outbred Hungarian population. In the sand lizard, the number of (GT/CA) n repeats was approximately three times higher than that for (CT/GA) n. The number of repeats and the frequency of microsatellites were within the range reported for other species. Three of nine microsatellite loci showed alleles that could not be amplified, which is in agreement with recent reports describing microsatellite “null alleles” as a common occurrence. We discuss the caution which this calls for when calculating paternity probabilities and when estimating between-population allelic differentiation. A potential problem with different mutation rates for alleles within the same locus is discussed.
Keywords: sand lizard; Lacerta agilis ; microsatellites; genetic variation
