Constructing Molecular Marker Linkage Maps of Chromosome 14Sh and 22Sh and QTL Mapping for Major Traits by Use of Substitution Lines of Gossypium hirsutum L.

CSB14Sh,which is isogenic for its recurrent parent TM-1 except for chromosome 14 short arm,was crossed with TM-1,and the F2 population was produced.A total of 3800 SSR primer pairs covering the whole genome were used to screen polymorphism among two parents,TM-1 and CSB14Sh,

Expression and Chromosomal Mapping of Mouse Gpx2 Gene Encoding the Gastrointestinal Form of Glutathione Peroxidase, GPX-GI

GPX-GI is a cytosolic tetrameric Se-dependent glutathione peroxidase, similar in properties to GPX-1. Unlike the almost ubiquitous GPX-1, GPX-GI is mainly expressed in the epithelium of gastrointestinal tract. GPX-GI contributes to at least fifty percent of GPX activity in rodent small intestmal epithelium. The total GPX activity consists of at least 70% of selenium-dependent GPX activity in this compartment.By analyzing a panel of mouse mterspecies DNA from the Jackson Laboratory's backcross resource,we mapped Gpx2 gene to mouse chromosome 12 between D12Mit4 and D12Mit5, near the Ccs1 locus which contains a colon cancer susceptibility gene. A pseudogene, Gpx2-ps is mapped to mouse chromosome 7.Comparison of Gpx2 gene expression in three pairs of C57BL/6Ha and ICR/Ha mice which are respectively resistant and sensitive to dimethylhydrazine-induced colon cancer, we found a higher Gpx2 mRNA level in C57BL/6Ha colon than ICR/Ha colon. Interestingly, a lower level of GPX activity is found in the resistant strain of mice. Because GPX-1 has three times higher specific activity than GPX GI, our data suggest that the decreased GPX activity may result from a higher level of Gpx2 gene expression in those cells co-express GPx1 gene

An Integrated Genetic,Physical and Transcript Map of Homoeologous Chromosomes 12 and 26 in Upland Cotton(Gossypium hirsutum L.)

While Upland cotton(Gossypium hirsutum L.) represents 95% of the world production,its genetic improvement is hindered by the shortage of effective genomic tools and resources.The

Polytene chromosomes of an Indian Himalayan black fly Simulium (Nevermannia) praelargum (Diptera:Simuliidae)

High quality polytene chromosome maps （n=3） of a Himalayan Simuliid Simulium praelargum Datta, 1973 are presented and represent the first cytological description of a taxon found in the feuerborni group, subgenus Nevermannia. Polytene chromosomes one （I） and two （II） are metacentric, chromosome three （III） is submetacentric with the length of each chromosome occupying 37.25 %, 31.36 % and 31.34 % of the total complement length, respectively. Typical simuliid diagnostic intergeneric chromosomal markers are found within the polytene complement of this species. The nucleolar organizer （N.O.） is found at the base of the short arm of chromosome one （IS）, the Ring of Balbiani （R.B.）, double bubble （D.B.） and triad occur in the short arm of chromosome two （IIS）, the Parabalbiani Ring （EB.） and grey band （gb） occur in the long arm of chromosome two （IIL） and the Blister （BL） and Capsule （Ca） occur in the short arm of chromosome three （IIIS）.Terminal bands at the end of IIIS are heterochromatinized and present atypically with respect to other simuliid fauna. Populations studied so far are unique among the Simuliidae in that they exhibit chromosome structural monomorphism. These high resolution polytene chromosome maps will form the basis for future cytological characterization and phylogenetic comparisons amongst members of the feuerborni group

Detailed deletion mapping on chromosome region 9p21 in human periampullary neoplasms

Objective To further define the extent of chromosome 9p21 deletion in periampullary neoplasms.Methods The loss of heterozygosity at 5 microsatellite polymorphic markers on chromosome 9p21 was detected by polymerase chain reaction (PCR), polyacrylamide gel electrophoresis (PAGE) and silver staining in 35 specimens of periampullary neoplasms and their matching blood samples.Results Fifty percent (4/8) of pancreatic cancer cases showed the loss of heterozygosity at one or more microsatellite loci, with the more frequent sites of D9S974 (37.5%) and D9S942 (28.6%), and some showing consecutive allelic loss. Sixty-two point five percent (5/8) of ampullary carcinoma cases showed loss of heterozygosity at one or more of the loci, frequent site of loss being D9S942 (42.9%) and the next most frequent being IFNA (37.5%) and D9S171 (37.5%). Loss of one locus was observed in 14.2% (1/7) of insulinoma. Conclusion The minimal common region of chromosome deletion in periampullary neoplasms is defined between the D9S974 and D9S942 loci within a 15?kb interval in 9p21, suggesting the involvement of a novel tumor suppressor gene in their carcinogenesis.

PCR analysis of Yq microdeletions in infertile males, a study from South India

AIM: To estimate the frequency of microdeletions in the long arm of Y-chromosome of 20 infertile males from South India. METHODS: Polymerase chain reaction (PCR) amplification using Y-specific STS of azoospermia factor (AZF) regions i.e., SY 84 for AZFa, SY 127 for AZFb and SY 254 for AZFc. RESULTS: Of the 20 infertile subjects 3 (15 %), one azoospermic and two oligozoospermic, showed microdeletions in the AZF region of Y-chromosome. CONCLUSION: The frequency of deletions involving AZF region of the Y-chromosome is 15 % in azoospermic and severely oligozoospermic infertile men. PCR amplification of AZF locus is useful for the diagnosis of microdeletions in the Y-chromosome.

Familial Wolff-Parkinson-White syndrome is linked to the loci on chromosome 7q3

OBJECTIVE: Wolff-Parkinson-White syndrome (WPW) is considered to be an autosomal dominant hereditary disease, but the gene is not identified. The objective of this study was to localize the genetic loci of Wolff-Parkinson-White syndrome. METHODS: Linkage analysis between the disease of Wolff-Parkinson-White syndrome and 3 STR (short tandem repeats) markers on 7q3 (D7S505, D7S688, and D7S483) was tested in 3 kindreds of the Wolff-Parkinson-White syndrome (101 numbers in total) by genotyping. RESULTS: Wolff-Parkinson-White syndrome was linked to the loci above. The maximum two-point Lod score detected at D7S505 was 6.4 at a recombination fraction (theta) of 0.1; the Lod score of D7S688, D7S483 was 5.3 vs 2.5. CONCLUSION: The gene of Wolff-Parkinson-White syndrome is located at 7q3.

Construction,Characterization,and Chromosomal Mapping of a Fosmid Library of the White-Cheeked Gibbon (Nomascus leucogenys)

Gibbons have experienced extensive karyotype rearrangements during evolution and represent an ideal model for studying the underlying molecular mechanism of evolutionary chromosomal rearrangements. It is anticipated that the cloning and sequence characterization of evolutionary chromosomal breakpoints will provide vital insights into the molecular force that has driven such a radical karyotype reshuffle in gibbons. We constructed and characterized a high-quality fosmid li- brary of the white-cheeked gibbon （Nomascus leucogenys） containing 192,000 non- redundant clones with an average insert size of 38 kb and 2.5-fold genome coverage. By end sequencing of 100 randomly selected fosmid clones, we generated 196 se- quence tags for the library. These end-sequenced fosmid clones were then mapped onto the chromosomes of the white-cheeked gibbon by fluorescence in situ hy- bridization~ and no spurious chimeric clone was detected. BLAST search against the human genome showed a good correlation between the number of hit clones and the number of chromosomes, an indication of unbiased chromosomal distribu- tion of the fosmid library. The chromosomal distribution of the mapped clones is also consistent with the BLAST search result against human and white-cheeked gibbon genomes. The fosmid library and the mapped clones will serve as a valu- able resource for further studying gibbons＇ chromosomal rearrangements and the underlying molecular mechanism as well as for comparative genomic study in the lesser apes.

Molecular characterization of thyroid peroxidase gene in porcine (sus scrofa)

Thyroid peroxidase （TPO） is the key enzyme involved in thyroid hormone synthesis. Several mutations in the TPO gene may affect the normal growth and development of mammals. In this study, the TPO gene was mapped, its expression level was determined in thyroid grand at the age of 1, 20, 45, 60, 90, 120 and 150 days for Jinhua pig, the alternative splicing form was searched and the single nucleotide polymorphism （SNP, A/G642） of TPO gene was analyzed. The results showed that the porcine TPO was mapped to 3q22-27, the expres- sion level of TPO was relatively stable among the various ages and two novel transcript variants in porcine TPO gene were found： the splicing variant TPO-2 lacked exon 8, while TPO-3 lacked exon 8 and exon 14, 15, 16. Moreover, we found that the SNP of A/G642in the fourteenth exon of TPO gene was significantly associated with ham weight （P 〈 0.05）. Our results provided important basis on the regulation and metabolism of the thyroid gland in animals.