Use of insertional mutagenesis to tag putative parasitic fitness genes in the Dutch elm disease fungus Ophiostoma novo-ulmi subsp. novo-ulmi

We used insertional mutagenesis to produce genetically tagged mutants of the Dutch elm disease fungus Ophiostoma novo-ulmi subsp. novo-ulmi. We first optimized transformation of O. novo-ulmi protoplasts by the restriction enzyme mediated integration method. A concentration of 80 U of HindIII with 108 fungal protoplasts and 5 mug of plasmid DNA was the most efficient for generating a high number of O. novo-ulmi mutants carrying a single insertion in their genome. Mycelium- and yeast-like growth kinetics of 24 O. novo-ulmi mutants were evaluated in vitro. Flanking sequences were successfully recovered in 8% of the transformants analyzed. Some mutant phenotypes appeared to result from gene disruption events, whereas others likely involved modifications of noncoding regions. Several nuclear loci that control vegetative growth and could potentially impact parasitic fitness were successfully tagged.     

Congenital syphilis in the past: slaves at Newton Plantation, Barbados, West Indies.

Hutchinson's incisors and Moon's molars are specific lesions of congenital syphilis. The extensive but fragmentary clinical literature on these conditions describes reduced dimensions and thin enamel in the permanent incisors and first molars, crowding and infolding of the first molar cusps, notching of the upper incisors, and apical hypoplasias of the permanent canines. A Barbados slave cemetery (ca. 1660-1820 AD) includes three individuals with these features, suggesting a frequency at birth of congenital syphilis in the population approaching 10%. These three cases show triple the frequency of all hypoplasias and more than seven times the frequency of pitting hypoplasia present in the remainder of the series. The recognizable congenital syphilis cases account for much of the remarkably high frequency of hypoplasias in the series as a whole. We infer that syphilis contributed substantially to morbidity, infant mortality, and infertility in this population. Presence or absence of congenital syphilis may account for much of the variability in health and mortality seen among nineteenth century African-American populations.     

Arberechtigung, Winterkleid und Melanismus vonUria mandtiiLicht

Ohne Zusammenfassung     

Replicated high-density genetic maps of two great tit populations reveal fine-scale genomic departures from sex-equal recombination rates

Linking variation in quantitative traits to variation in the genome is an important, but challenging task in the study of life-history evolution. Linkage maps provide a valuable tool for the unravelling of such trait−gene associations. Moreover, they give insight into recombination landscapes and between-species karyotype evolution. Here we used genotype data, generated from a 10k single-nucleotide polymorphism (SNP) chip, of over 2000 individuals to produce high-density linkage maps of the great tit (Parus major), a passerine bird that serves as a model species for ecological and evolutionary questions. We created independent maps from two distinct populations: a captive F2-cross from The Netherlands (NL) and a wild population from the United Kingdom (UK). The two maps contained 6554 SNPs in 32 linkage groups, spanning 2010 cM and 1917 cM for the NL and UK populations, respectively, and were similar in size and marker order. Subtle levels of heterochiasmy within and between chromosomes were remarkably consistent between the populations, suggesting that the local departures from sex-equal recombination rates have evolved. This key and surprising result would have been impossible to detect if only one population was mapped. A comparison with zebra finch Taeniopygia guttata, chicken Gallus gallus and the green anole lizard Anolis carolinensis genomes provided further insight into the evolution of avian karyotypes.