Development of a novel recessive genetic male sterility system for hybrid seed production in maize and other cross-pollinating crops.

We have developed a novel hybridization platform that utilizes nuclear male sterility to produce hybrids in maize and other cross-pollinating crops. A key component of this platform is a process termed Seed Production Technology (SPT). This process incorporates a transgenic SPT maintainer line capable of propagating nontransgenic nuclear male-sterile lines for use as female parents in hybrid production. The maize SPT maintainer line is a homozygous recessive male sterile transformed with a SPT construct containing (i) a complementary wild-type male fertility gene to restore fertility, (ii) an α-amylase gene to disrupt pollination and (iii) a seed colour marker gene. The sporophytic wild-type allele complements the recessive mutation, enabling the development of pollen grains, all of which carry the recessive allele but with only half carrying the SPT transgenes. Pollen grains with the SPT transgenes exhibit starch depletion resulting from expression of α-amylase and are unable to germinate. Pollen grains that do not carry the SPT transgenes are nontransgenic and are able to fertilize homozygous mutant plants, resulting in nontransgenic male-sterile progeny for use as female parents. Because transgenic SPT maintainer seeds express a red fluorescent protein, they can be detected and efficiently separated from seeds that do not contain the SPT transgenes by mechanical colour sorting. The SPT process has the potential to replace current approaches to pollen control in commercial maize hybrid seed production. It also has important applications for other cross-pollinating crops where it can unlock the potential for greater hybrid productivity through expanding the parental germplasm pool.

[Increased level of prostate-specific antigen: a diagnostic marker of hyperandrogenism women].

OBJECTIVE: To determine whether the increased level of serum prostate-specific antigen (PSA) could be used as a diagnostic marker of hyperandrogenism in women. METHODS: Forty-five female patients with hyperandrogenism and 50 healthy control women were detected for the levels of serum PSA, testosterone (T), sex hormone binding globulin (SHBG) and dehydroepiandrosterone sulfate (DHEA-S). The results were statistically analyzed. RESULTS: The level of serum PSA was found to be significantly higher in the hyperandrogenism patients than in the healthy controls (9.72 +/- 1.39 pg/ml vs 3.56 +/- 0.44 pg/ml, P < 0.01), and it showed a weak positive correlation with T (r = 0.226, P < 0.05) and DHEA-S (r = 0.255, P < 0.05), and a weak negative correlation with SHBG (r = -0,228, P < 0.05). CONCLUSION: The increased level of PSA could be used as a diagnostic marker of hyperandrogenism in females.

[Development of radioimmunoassay for human sperm protein 17].

OBJECTIVE: To develop a method of radioimmunoassay for human sperm protein 17(Sp17) determination. METHODS: Anti-recombinant human Sp17 antibody was prepared, the labeling of 125I-rhSp17 performed by chloramine T method, and radioimmunoassay of Sp17 developed. RESULTS: The assay range was 3.3 to approximately 800 microg/L, the sensitivity was 2.0 microg/L, and the intra- and inter-assay coefficients of variation (CV) were 7.5% to approximately 9.8% and 8.2% to approximately 13.2%, respectively. The serum Sp17 level in normal subjects was (15.60 +/- 7.66) microg/L (n = 59). CONCLUSION: This radioimmunoassay of Sp17 fulfills the reasonable requirements of clinical routine and scientific studies in terms of specificity, sensitivity and practicability. Measurement of Sp17 concentration is useful for assessing its native distribution and aberrant expression.

[Plasma endothelin-1 in patients with prostate cancer and its clinical significance].

OBJECTIVE: To investigate plasma endothelin-1 (ET-1) level in patients with prostate cancers and its clinical significance. METHODS: Plasma ET-1 level was measured by radioimmunoassay in 31 patients of prostate cancer (23 with non-HRPC, 8 with HRPC) and 26 patients of BPH. RESULTS: Compared with each other of the ET-1 level, there were no significant difference among the BPH group,non-HRPC group and HRPC group. No significant difference was found either between bone metastasis (BM) and non- BM, between high and middling differentiation prostate cancer group, as well as in different PSA level groups (P >0.05). But the ET-1 level in low differentiation prostate cancer was notably lower than those of the high and middle respectively (P < 0.05). CONCLUSION: To detect plasma endothelin-1 (ET-1) level is not a useful method to evaluate the development and the prognosis of prostate cancer.

A chimeric ecdysone receptor facilitates methoxyfenozide-dependent restoration of male fertility in ms45 maize.

A mutation in the maize Ms45 gene results in abortion of microspore development and a male-sterile phenotype. MS45 protein has been localized to the tapetum and maximally expressed in anthers at the early vacuolate stage of microspore development. Molecular complementation analysis determined that a transformed copy of the gene fully restored fertility to ms45 maize. In this report, using phenotypic complementation as an assay, chimeric transcriptional activators were expressed to regulate a gal:MS45 gene and test the ability of a multi-component system to restore male fertility. A high frequency of phenotypic complementation was observed when either C1-GAL4 or VP16-GAL4 activators were transcribed by promoters that expressed at a stage of anther development that precedes the early vacuolate stage of microsporogenesis. For the conditional regulation of male fertility, these transcriptional activators were modified by the addition of regions that include the ligand-binding domain from the European corn borer ecdysone receptor to generate the nuclear receptors C1-GAL4-EcR (CGEcR) and VP16-GAL4-EcR (VGEcR). These chimeric receptors were introduced with the gal:MS45 gene into ms45 maize, and in the absence of ligand, these plants were male sterile. In contrast, application of the ecdysone agonist, methoxyfenozide, to plants containing either a constitutive (Ubiquitin1) or anther-specific (maize 5126) VGEcR resulted in the restoration of fertility to ms45 plants grown in either the greenhouse or in the field.