Check out our New Publishers' Select for Free Articles

Biochemical Genetics (v.43, #5-6)

Polymorphism for Transforming Growth Factor Beta 1-509 (TGF-B1-509): Association with Endometriosis by Yao-Yuan Hsieh; Chi-Chen Chang; Fuu-Jen Tsai; Ching-Tien Peng; Lian-Shun Yeh; Cheng-Chieh Lin (pp. 203-210).

Transforming growth factor beta (TGF-B) family members are multi-functional cytokines that play a key role in cellular growth, proliferation, and differentiation. The aim of the study was to investigate whether the TGF-B1-509 gene polymorphism could be used as a marker of susceptibility in endometriosis. Women were divided into two groups: endometriosis (n = 150) and non-endometriosis (n = 159). Polymorphisms for TGF-B1-509 genes were amplified by polymerase chain reaction and detected after restriction enzyme digestion. Genotypes and allelic frequencies in both groups were compared. Genotype proportions and allele frequencies of TGF-B1 gene polymorphisms differed significantly in both groups. Proportions of C homozygote, heterozygote, and T homozygote for TGF-B1 gene polymorphisms were 9.3/61.3/29.4% in the endometriosis group and 41.3/58.5/0% in the non-endometriosis group. Alleles C and T for TGF-B1 gene polymorphism were 40/60% (endometriosis) and 70.8/29.2% (non-endometriosis). Association of endometriosis with TGF-B1-509 gene polymorphism exists. T homozygote and T allele for TGF-B1 are associated with higher susceptibility to endometriosis.

Keywords: cytokine; endometriosis; polymorphism; transforming growth factor

Genetic Structure of Blastocerus dichotomus Populations in the Paraná River Basin (Brazil) Based on Protein Variability by E. J. F. de Oliveira; J. E. Garcia; E. P. B. Contel; J. M. B. Duarte (pp. 211-222).

The population structure of 147 marsh deer (Blastocerus dichotomus) from three areas in the Paraná River basin, Brazil, was studied by observing protein polymorphism at 17 loci. Six loci were polymorphic and 11 monomorphic. The proportion of polymorphic loci (P) was 35.29% and the average heterozygosity (H) was 6.31%. Wright's F_ST indicated that only 4.9% of the total variation in allelic frequencies was due to genetic differences between the three groups. The high value of F_IS (0.246) indicated inbreeding in the marsh deer. Genetic distance values (D = 0.014–0.051) showed little divergence between the three areas. We suggest that probable mechanisms accounting for the genetic structure are female phylopatry and polygyny and also that inbreeding has resulted from decreasing areas of wetland leading to isolation, overhunting, and diseases transmitted by cattle.

Keywords: Blastocerus dichotomusmarsh deer; genetic variability; population genetics

Genetic Polymorphism of Aldehyde Dehydrogenase 2 (ALDH2) in a Chinese Population: Gender, Age, Culture, and Genotypes of ALDH2 by Huai-Rong Luo; Yedy Israel; Guang-Chou Tu; C. J. Peter Eriksson; Ya-Ping Zhang (pp. 223-227).

Local Base Order Influences the Origin of ccr5 Deletions Mediated by DNA Slip Replication by Chi-Yu Zhang; Ji-Fu Wei; Shao-Heng He (pp. 229-237).

CCR5 is a seven-transmembrane G-protein-coupled receptor that binds the CC-chemokines including RANTES, eotaxin, MIP-1α and β. CCR5 serves as an essential coreceptor for cell entry of R5 (macrophage-tropic, nonsyncytium-inducing) strains of HIV-1. To date, four deletions have been found in human and primate ccr5. There is little evidence, however, on how these deletion mutations occur. In the present study, we analyzed ccr5 sequences of both mutants and wild type and found that direct repeats flanked the breakpoints of the deletions, suggesting that these deletions resulted from slipped mispairing during DNA replication. Of particular interest was the location of these deletions in or near the regions with higher negative FORS-D values. High negative FORS-D values stand for high stem-loop potential determined by base order and influence mainly the formation of stem-loop structures. Therefore, the particular location of these deletions suggests that the local sequence of bases might be important in the initiation of deletions mediated by DNA slip replication in concert with direct repeats.

Keywords: ccr5deletion; direct repeats; stem-loop potential; slip replication

Detection of Low Genetic Variation in a Critically Endangered Chinese Pine, Pinus squamata, Using RAPD and ISSR Markers by Zhi-Yong Zhang; Yong-Yan Chen; De-Zhu Li (pp. 239-249).

With only 32 individuals in the northeastern corner of Yunnan Province, China, Pinus squamata is one of the most endangered conifers in the world. Using two classes of molecular markers, RAPD and ISSR, its very low genetic variation was revealed. Shannon's index of phenotypic diversity (I) was 0.030, the mean effective number of alleles per locus (A_e) was 1.032, the percentage of polymorphic loci (P) was 6.45, and the expected heterozygosity (H_e) was 0.019 at the species level based on RAPD markers. The results of ISSR were consistent with those detected by RAPD but somewhat higher (I = 0.048, A_e = 1.042, P = 12.3, H_e = 0.029). The genetic variation of the subpopulation on the southwest-facing slope was much higher than that of the subpopulation on the northeast-facing slope, which may be attributed to the more diverse environment on the southwest-facing slope. The genetic differentiation between the two subpopulations was very low. The between-subpopulation variabilities, Φ_ST, calculated from RAPD and ISSR data were 0.011 and 0.024. Because of the lack of fossil records and geological historical data, it was difficult to explain the extremely low genetic diversity of the species. We postulate that this ancient pine might have experienced strong bottlenecks during its long evolutionary history, which caused the loss of genetic variation. Genetic drift and inbreeding in post-bottlenecked small populations may be the major forces that contribute to low genetic diversity. Human activities such as logging may have accelerated the loss of genetic diversity in P. squamata.

Keywords: Pinus squamataRAPD; ISSR; genetic variation; endangered species

Phylogenetic Relationships of Sheep Populations from Coastal Areas in East Asia by Shengxia Lu; Hong Chang; Lei Du; Kenji Tsunoda; Wei Sun; Zhangping Yang; Guobing Chang; Dejun Ji (pp. 251-260).

Using the method of random sampling in typical colonies of the central area of the habitat and several electrophoresis techniques, the variations of 12 structural loci encoding blood protein of 60 Small-tailed Han sheep were examined and compared with those of four other sheep populations from coastal areas in East Asia to explore their phylogenetic relationships. Average heterozygosity of the five populations was: Kharkhorin sheep 0.3447, Ulaanbaatar sheep 0.3285, Small-tailed Han sheep 0.3157, Hu sheep 0.3884, and Cham Tribe sheep 0.2300. The earlier researchers' conclusion through documentary research, indicating that Small-tailed Han sheep and Hu sheep both evolved from Mongolian sheep, was further verified by the results of this study. Hu sheep, Small-tailed Han sheep, and Cham Tribe sheep were decreasingly affected by the bloodline of Mongolian sheep. A partial founder population, i.e., Mongolian sheep forming current Small-tailed Han sheep, possibly made a contribution to the bloodline of Cham Tribe sheep.

Keywords: sheep; structural loci; East Asia; phylogenetic relationships

Genetic Diversity and Population Differentiation of Liaoning Weedy Rice Detected by RAPD and SSR Markers by Guo-qin Yu; Ying Bao; Chun-hai Shi; Chang-qin Dong; Song Ge (pp. 261-270).

Weedy rice refers to populations of usually annual Oryza species that diminish farmer income through reduction of grain yield and lowered commodity value at harvest. The genetic diversity and population genetic structure of weedy rice in Liaoning Province were studied by RAPD and SSR markers. The results indicate that the level of genetic diversity of Liaoning weedy rice is very low, with polymorphic loci being only 3.70% (RAPDs) and 47.62% (SSRs). On the other hand, high genetic differentiation was found among populations, in particular between two regions (Shenyang and Dandong), with Fst values of 0.746 (RAPDs) and 0.656 (SSRs), suggesting that more than two thirds of the genetic variation resides among regions. Combined with our investigations of cultural traditions, the low level of genetic diversity in Liaoning Province is attributed to its narrow genetic background enhanced by exchanges of cultivar seeds, whereas the high genetic differentiation between the two regions is most likely the result of different founding parents and gene flow from local rice varieties to weedy rice. The rice cultivars in the two regions are all local varieties and are different genetically. A comparison of the two marker systems demonstrates that SSR is more informative and powerful in terms of the assessment of genetic variability, although both RAPD and SSR provide useful genetic information on weedy rice.

Keywords: genetic diversity; RAPD; SSR; weedy rice

A Novel Zinc Finger Gene ZNF468 with Two Co-Expressional Splice Variants, ZNF468.1 and ZNF468.2 by Liyun Sun; Shaohua Gu; Ni Li; Dan Zheng; Yaqiong Sun; Dan Li; Chaoneng Ji; Kang Ying; Yi Xie; Yumin Mao (pp. 271-286).

A novel human zinc finger protein encoding gene ZNF468 was obtained from a fetal brain cDNA library. By BLAST-N analysis we found two different splice variants. We termed the two splice variants ZNF468.1 and ZNF468.2. By BLAST search against the human genome database, ZNF468 was mapped to 19q13.4. The ZNF468.1 cDNA has four exons, and the ZNF468.2 cDNA has one more, between the third and fourth exon. This extra exon creates a difference between the deduced protein N-termini of the two splice variants. The ZNF468.1 cDNA is 3906 bp in length, encoding a 522a a protein, and ZNF468.2 is 4024 bp, encoding a 469-aa-protein. Both proteins contain 11 C2H2-type zinc finger motifs at their C-termini. The N-terminus of the deduced protein of ZNF468.1 has a well-conserved Krüppel-associated box (KRAB) domain that consists of KRAB boxes A and B, whereas the protein of ZNF468.2 does not have the {KRAB} domain. Tissue distribution of the ZNF468 gene indicates that the two splice variants are widely expressed in normal human tissues, except in heart and brain, and they are also co-expressional.

Keywords: ZNF468KRAB domain; C2H2 zinc finger; expression pattern

Genetic Background Influences P/Q-type Ca²⁺ Channel α_1A Subunit mRNA Expression in Olfactory Bulb and Reproductive Ability of N-type Ca²⁺ Channel α_1B Subunit-Deficient Mice by Eiki Takahashi; Takeshi Nagasu (pp. 287-298).

The Ca²⁺ channel α_1B subunit is a pore-forming component capable of generating N-type Ca²⁺ channel activity. Although the N-type Ca²⁺ channel plays a role in a variety of neuronal functions, α_1B-deficient mice did not show apparent behavioral abnormality. In a previous study, we observed a compensatory increase of mRNA expression of the P/Q-type Ca²⁺ channel α_1A subunit gene in olfactory bulb of α_1B-deficient mice with a CBA × C57BL/6 background; these mice showed a normal reproductive ability. In this study, we found that the mRNA expression level of the α_1A subunit was the same in olfactory bulb of wild, heterozygous, and homozygous α_1B-deficient mice with a CBA/JN background, and the homozygous male mice produced no offspring. These results suggest that the genetic background influences α_1A subunit mRNA expression and reproductive ability in α_1B-deficient mice.

Keywords: congenic strain; genetic background; olfactory bulb; compensatory mechanism; P/Q-type Ca²⁺ channel α_1A gene

Polymorphic Study of Equine Antiviral MXA Gene by Lin Hua Ju; Akio Onogi; Junji Ueda; Koji Yamada; Yuichiro Nakatsu; Mika Ohe; Hiroshi Hata; Kazuya Sasaki; Tomomasa Watanabe (pp. 299-305).

Population Genetic Structure of the Yangtze Finless Porpoise (Neophocaena phocaenoides asiaeorientalis): Implications for Management and Conservation by Jin-Song Zheng; Jun-Hong Xia; Shun-Ping He; Ding Wang (pp. 307-320).

Understanding the population genetic structure is a prerequisite for conservation of a species. The degree of genetic variability characteristic of the mitochondrial DNA control region has been widely exploited in studies of population genetic structure and can be useful in identifying meaningful population subdivisions. To estimate the genetic profile of the Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis), an endangered freshwater population endemic to China, the complete mtDNA control region was examined in 39 individuals belonging to seven different stocks inhabiting the middle and lower reaches of the Yangtze River. Very low genetic diversity was found (nucleotide diversity 0.0011± 0.0002 and haplotypic diversity 0.65± 0.05). The mtDNA genetic pattern of the Yangtze population appears to indicate a founder event in its evolutionary history and to support the marine origin for this population. Analyses by F_st and Φ_st yielded statistically significant population genetic structure (F_st = 0.44, P < 0.05; Φ_st = 0.36, P < 0.05). These results may have significant implications for the management and conservation of the Yangtze finless porpoise in the future.

Keywords: Yangtze finless porpoise; mtDNA; genetic structure; gene flow; conservation

Mice with the Enhanced Green Fluorescent Protein Gene Knocked in to Chromosome 11 Exhibit Normal Transmission Ratios by Jan Klysik; Jeffrey D. Singer (pp. 321-333).

Meiotic recombination between homologous chromosomes can be suppressed within a chosen segment by a regional inversion. In mice, this feature can be engineered and conveniently used in genetic screens to maintain chemically induced mutations within the homologous chromosome. The efficiency of an inversion-based mutagenesis screen can be substantially enhanced provided that the inversion chromosome and its wild-type (WT) homologue are both visibly tagged by two different coat color markers. Dual tagging eliminates labor associated with molecular genotyping. Previously, we reported the generation of the In(11)10Brd strain of mice carrying K14-agouti tagging a 30-cM inversion between the Trp53 and Egfr loci on mouse chromosome 11. Since K14-agouti causes yellowing of ears and tails, the In(11)10Brd mice are easily distinguishable from their WT littermates. In this paper, we describe the construction of a second strain of mice that carry the enhanced green fluorescent protein (EGFP) transgene at the Egfr locus. The EGFP carriers are visually recognizable by emitting green fluorescent light upon UV illumination. We found that the EGFP function was transmitted from one generation to another with expected Mendelian frequencies, and no detrimental effects of EGFP expression were detected in hemizygous or homozygous animals. The EGFP mice together with the previously generated In(11)10Brd inversion carriers constitute a complete set of reagents required for initiation of a regional ENU mutagenesis screen to address functionally more than one-third of mouse chromosome 11.

Keywords: enhanced green fluorescent protein; epidermal growth factor receptor; mouse chromosome 11; knock-in mouse; ENU mutagenesis

Sections

Personal tools

Biochemical Genetics (v.43, #5-6)

Sections

Personal tools

Local resources

Biochemical Genetics (v.43, #5-6)