Somaclonal variation from Sorghum bicolor (L.) Moench cell culture

Plant Cell, Tissue and Organ Culture (PCTOC) - Sorghum bicolor (L.) Moench, plants were regenerated from 4 to 5 month old callus cultures originally derived from seedling explants. Somaclonal...     

Isolation of mitochondrial DNA sequences that distinguish male-sterility-inducing cytoplasms in Sorghum bicolor (L.) Moench

We have demonstrated that sorghum DNA sequences of mitochondrial origin can be used to distinguish different male-sterility-inducing cytoplasms. Six DNA clones containing single-copy mitochondrial sequences were hybridized on Southern blots to restriction enzyme-digested DNA of 28 sorghum lines representing sources of different cytoplasmic male-sterility (CMS) groups. Four cytoplasmic types were defined on the basis of the pattern of DNA fragments detected. Similar analyses of 50 additional diverse sorghum accessions suggested that three of the four cytoplasmic types may be diagnostic for CMS. Also, three other cytoplasmic types were discovered. These and other mitochondrial DNA clones may be useful molecular tools for “fingerprinting” sterility-inducing cytoplasms in breeding programs, determining cytoplasmic diversity among germ plasm accessions, and identifying new sources of cytoplasm that induce male sterility.     

Recombinant human follicle-stimulating hormone produces more oocytes with a lower total dose per cycle in assisted reproductive technologies compared with highly purified human menopausal gonadotrophin: a meta-analysis

Background  

Human menopausal gonadotrophins and recombinant human follicle stimulating hormone are the two main gonadotrophin products utilized for controlled ovarian stimulation in assisted reproductive technologies. In this meta-analysis, the number of oocytes was designated as the most relevant endpoint directly resulting from ovarian stimulation, and therefore where the drug effect may be estimated with the best sensitivity.     

The Human Oocyte Preservation Experience (HOPE) a phase IV, prospective, multicenter, observational oocyte cryopreservation registry

Background  

It has been recommended by the American Society of Clinical Oncology and the American Society of Reproductive Medicine that options to preserve fertility be presented at the outset of treatment for cancer. This recommendation may have arisen, in part, to the increasing survival of patients with cancer and the realization that certain forms of cancer treatment can lead to infertility. One option for these patients, particularly those with ethical or religious objections to freezing embryos is oocyte cryopreservation. However universal acceptance of these procedures has yet to be established, most likely due to a poor history of success and concerns that there has yet to be a comprehensive approach to evaluating these techniques. In light of this, a registry of patients undergoing oocyte cryopreservation, called the HOPE registry, is being implemented.     

Fine mapping of the Pc locus of Sorghum bicolor, a gene controlling the reaction to a fungal pathogen and its host-selective toxin

Milo disease in sorghum is caused by isolates of the soil-borne fungus Periconia circinata that produce PC-toxin. Susceptibility to milo disease is conditioned by a single, semi-dominant gene, termed Pc. The susceptible allele (Pc) converts to a resistant form (pc) spontaneously at a gametic frequency of 10⁻³ to 10⁻⁴. A high-density genetic map was constructed around the Pc locus using DNA markers, allowing the Pc gene to be delimited to a 0.9 cM region on the short arm of sorghum chromosome 9. Physically, the Pc-region was covered by a single BAC clone. Sequence analysis of this BAC revealed twelve gene candidates. Several of the predicted genes in the region are homologous to disease resistance loci, including one NBS-LRR resistance gene analogue that is present in multiple tandem copies. Analysis of pc isolines derived from Pc/Pc sorghum suggests that one or more members of this NBS-LRR gene family are the Pc genes that condition susceptibility.     

Alignment of genetic maps and QTLs between inter- and intra-specific sorghum populations

To increase the value of associated molecular tools and also to begin to explore the degree to which interspecific and intraspecific genetic variation in Sorghum is attributable to corresponding genetic loci, we have aligned genetic maps derived from two sorghum populations that share one common parent (Sorghum bicolor L. Moench accession BTx623) but differ in morphological and evolutionarily distant alternate parents (S. propinquum or S. bicolor accession IS3620C). A total of 106 well-distributed DNA markers provide for map alignment, revealing only six nominal differences in marker order that are readily explained by sampling variation or mapping of paralogous loci. We also report a total of 61 new QTLs detected from 17 traits in these crosses. Among eight corresponding traits (some new, some previously published) that could be directly compared between the two maps, QTLs for two (tiller height and tiller number) were found to correspond in a non-random manner (P<0.05). For several other traits, correspondence of subsets of QTLs narrowly missed statistical significance. In particular, several QTLs for leaf senescence were near loci previously mapped for ‘stay-green’ that have been implicated by others in drought tolerance. These data provide strong validation for the value of molecular tools developed in the interspecific cross for utilization in cultivated sorghum, and begin to separate QTLs that distinguish among Sorghum species from those that are informative within the cultigen (S. bicolor). Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. K.F. Schertz: deceased