The microbial community and sulfur oxygenase reductases of metagenomic DNA from bioreactors treating gold-bearing concentrates were studied by 16S rRNA library, real-time polymerase chain reaction (RT-PCR), conventional cultivation, and molecular cloning. Results indicated that major bacterial species were belonging to the genera Acidithiobacillus, Leptospirillum, Sulfobacillus, and Sphingomonas, accounting for 6.3, 66.7, 18.8, and 8.3%, respectively; the sole archaeal species was Ferroplasma sp. (100%). Quantitative RT-PCR revealed that the 16S rRNA gene copy numbers (per gram of concentrates) of bacteria and archaea were 4.59 x 10(9) and 6.68 x 10(5), respectively. Bacterial strains representing Acidithiobacillus, Leptospirillum, and Sulfobacillus were isolated from the bioreactors. To study sulfur oxidation in the reactors, pairs of new PCR primers were designed for the detection of sulfur oxygenase reductase (SOR) genes. Three sor-like genes, namely, sor (Fx), sor (SA), and sor (SB) were identified from metagenomic DNAs of the bioreactors. The sor (Fx) is an inactivated SOR gene and is identical to the pseudo-SOR gene of Ferroplasma acidarmanus. The sor (SA) and sor (SB) showed no significant identity to any genes in GenBank databases. The sor (SB) was cloned and expressed in Escherichia coli, and SOR activity was determined. Quantitative RT-PCR determination of the gene densities of sor (SA) and sor (SB) were 1,000 times higher than archaeal 16S rRNA gene copy numbers, indicating that these genes were mostly impossible from archaea. Furthermore, with primers specific to the sor (SB) gene, this gene was PCR-amplified from the newly isolated Acidithiobacillus sp. strain SM-1. So far as we know, this is the first time to determine SOR activity originating from bacteria and to document SOR gene in bioleaching reactors and Acidithiobacillus species.

ABSTRACT. We analyzed the genetic diversity of 115 barley germplasms, including 112 landraces and three new barley cultivars grown in the Shanghai region, using a set of 11 SSR markers. Sixtysix alleles were observed at the 11 SSR loci, ranged from three to ten, with a mean of six alleles per locus. The polymorphism information content ranged from 0.568 to 0.853, with a mean of 0.732, indicating considerable genetic variation in barley in the Shanghai area. Clustering analysis indicated that these barley accessions could be divided into two categories (A and B). Ninety-seven six-rowed barley cultivars were classified in the A category; sixteen two-rowed and two six-rowed barley cultivars were classified in the B category. This demonstrated genetic differences between two-rowed and six-rowed barley varieties. In addition, we found that the three new barley cultivars are closely related.

A number of variables were investigated in 46 men who had stopped taking gossypol for their predictive association with the degree and time of recovery of spermatogenesis. Thirty-nine (87%) of the men were azoospermic at cessation of gossypol treatment. In those with sperm present the geometric mean concentration and total sperm count were 8.3 X 10(6)/ml and 30.7 X 10(6), respectively. Twenty-eight men (61%) recovered to a defined threshold of spermatogenic function (sperm concentration greater than or equal to 20 X 10(6)/ml), with a median recovery time of 1.1 years. However, 18 men (39%) had not recovered to this degree of spermatogenic function after a median follow-up of 1.9 years and, of these, 10 (22%) remained azoospermic. The influence of individual baseline variables on the time to defined recovery was examined using Kaplan-Meier curves for groups and their joint effect by Cox's regression model. The failure of recovery was strongly associated with longer treatment, greater total dose of gossypol, smaller testicular volume, elevated FSH concentrations and, to a lesser extent, with greater body weight.

This paper reports the methods of construction of gene-targeting vector for transformation of silkworm, Bombyx mori L. The genomic DNA was isolated from the posterior silk gland of the fifth-instar silkworm larvae. The short fragment (0.5 kb) and long fragment (5 kb) of the fibroin light-chain gene were obtained by polymerase chain reaction (PCR) analysis with special primers and genome DNA as templates and then recombined with pBlueselect vector into pBs-FS-FL. The target green flourescent protein (GFP) gene, was derived from pGEP-1 vector and recombined with pUC19 vector into pUCG vector. GFP was recovered after cutting with restriction endonucleases, PstI and BamHI. Finally, GFP was recombined with pBs-FS-FL into gene-targeting vector, pBs-FS-GFP-FL.