The segregation of a bacterial plasmid, the sex factor F', has been investigated in a cell-division mutant of Escherichia coli which produces small anucleate cells (minicells). Significant amounts of isotopically labeled DNA segregate into minicells dependent upon the presence of F'. Minicells containing F'Gal or F'(lambda) are shown to donate the plasmid in conjugation. These results demonstra...

The partition-proficient mini-F plasmid pXX325 was stably maintained in the mukB null mutant, which is defective in chromosome partitioning into the two daughter cells. In the null mutant, the plasmid was partitioned into both nucleate and anucleate daughter cells, independently of host chromosomes.

BACKGROUND Decisions involving risk often must be made under stressful circumstances. Research on behavioral and brain differences in stress responses suggest that stress might have different effects on risk taking in males and females. METHODOLOGY/PRINCIPAL FINDINGS In this study, participants played a computer game designed to measure risk taking (the Balloon Analogue Risk Task) fifteen min...

Sex-role reversal represents a formidable challenge for evolutionary biologists, since it is not clear which ecological, life-history or social factors facilitated conventional sex roles (female care and male-male competition for mates) to be reversed (male care and female-female competition). Classic theories suggested ecological or life-history predictors of role reversal, but most studies fa...

This paper describes computational and experimental work on pattern formation in Drosophila egg development (oogenesis), an established experimental model for studying cell fate diversification in developing tissues. Epidermal growth factor receptor (EGFR) is a key regulator of pattern formation and morphogenesis in Drosophila oogenesis. EGFR signalling in oogenesis can be genetically manipulat...

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In many mammalian species, it is known that males and females differ in place learning ability. The performance by men and women is commonly reported to also differ, despite a large amount of variability and ambiguity in measuring spatial abilities. In the non-human literature, the gold standard for measuring place learning ability in mammals is the Morris water task. This task requires subject...