Sister chromatid cohesion is essential for cell division. During meiosis, it is also required for proper synapsis of pairs of sister chromatids and for chiasma formation and maintenance. Since mammalian oocytes remain arrested in late prophase for a very long period-up to five decades in humans-the preservation of cohesion throughout this period is a formidable challenge. Mouse models with cohe...

We present an analysis of crossover interference in the mouse genome, on the basis of high-density genotype data from two reciprocal interspecific backcrosses, comprising 188 meioses. Overwhelming evidence was found for strong positive crossover interference with average strength greater than that implied by the Carter-Falconer map function. There was some evidence for interchromosomal variatio...

The gol-1, gol-2, alb-1 and spa-1 mutations affect pigment pattern in the zebrafish. We show here that these loci are unlinked to each other. In addition, gene-centromere distances were determined for these loci by analysis of half-tetrads obtained by the inhibition of the second meiotic division. The fractions of tetratype (second-division segregation) tetrads range from 0.24 (spa-1) to 0.89 (...

The segregation of chromosomes 13 distinguishable by Q band fluorescent polymorphisms has been studied in three families with retinoblastoma. The recombination fraction for two of these families and four families previously reported did not differ significantly from 50%. Since a high recombination fraction has been predicted from chiasma frequency between the centromere of chromosome 13 and 13q...

Accepted 16 October 1995 A 44-year-old man had suffered from headache, general fatigue and impotence for three months. Physical examination revealed a bitemporal visual field defect. Skull X-ray films showed ballooning of the sella turcica. Magnetic resonance imaging (MRI) revealed an intrasellar cystic mass compressing optic chiasma (figure). The cyst was removed by a transsphenoidal approach....

The unloaded human finger with a taut deep flexor functions as a bi-articular chain. because the angulations of the distal two joints are mechanically coupled. In this chain two flexors exist: the superficial and deep flexor. However, for elementary control of the unloaded finger. only one flexor is required. This puts forward the question of which flexor is most suited for unloaded finger cont...

The co-existence of multiple variants in the axilla has been rarely documented. Hence, we report the multiple variations of axillary structures and axillary arch. During a dissection of axilla of adult male cadaver, following variations were encountered. a) One superficial and complete type of axillary arch on left axilla only. b) Venous chiasma between the basilic vein and brachial vein of bot...

The importance of vision in the behavior of animals, from invertebrates to primates, has led to a good deal of interest in how projection neurons in the retina make specific connections with targets in the brain. Recent research has focused on the cellular interactions occurring between retinal ganglion cell (RGC) axons and specific glial and neuronal populations in the embryonic brain during f...