Kinematics of chiropteran shoulder girdle in flight.

New data on the mechanisms of movements of the shoulder girdle and humerus of bats are described; potential mobility is compared to the movements actually used in flight. The study was performed on the basis of morphological and functional analysis of anatomical specimens of 15 species, high speed and high definition filming of two species and X-ray survey of Rousettus aegyptiacus flight. Our observations indicate that any excursions of the shoulder girdle in bats have relatively small input in the wing amplitude. Shoulder girdle movements resemble kinematics of a crank mechanism: clavicle plays the role of crank, and scapula-the role of connecting rod. Previously described osseous "locking mechanisms" in shoulder joint of advanced bats do not affect the movements, actually used in flight. The wing beats in bats are performed predominantly by movements of humerus relative to shoulder girdle, although these movements occupy the caudal-most sector of available shoulder mobility.

Cytologically integrated physical restriction fragment length polymorphism maps for the barley genome based on translocation breakpoints.

We have developed a new technique for the physical mapping of barley chromosomes using microdissected translocation chromosomes for PCR with sequence-tagged site primers derived from >300 genetically mapped RFLP probes. The positions of 240 translocation breakpoints were integrated as physical landmarks into linkage maps of the seven barley chromosomes. This strategy proved to be highly efficient in relating physical to genetic distances. A very heterogeneous distribution of recombination rates was found along individual chromosomes. Recombination is mainly confined to a few relatively small areas spaced by large segments in which recombination is severely suppressed. The regions of highest recombination frequency (

The physical relationship of barley chromosome 5 (1H) to the linkage groups of rice chromosomes 5 and 10.

Using a recently developed polymerase chain reaction (PCR)-mediated approach for physical mapping of single-copy DNA sequences on microisolated chromosomes of barley, sequence-tagged sites of DNA probes that reveal restriction fragment length polymorphisms (RFLP) localized on the linkage maps of rice chromosomes 5 and 10 were allocated to cytologically defined regions of barley chromosome 5 (1H). The rice map of linkage group 5, of about 135 cM in size, falls into two separate parts, which are related to the distal portions of both the short and long arms of the barley chromosome. The markers on the rice map of chromosome 5 were found to be located within regions of the barley chromosome which show high recombination rates. The map of rice chromosome 10, of about 75 cM in size, on the other hand, is related to an interstitial segment of the long arm of chromosome 5 (1H) which is highly suppressed in recombination activity. For positional cloning of genes of this homoeologous region from the barley genome, the small rice genome will probably prove to be a useful tool. No markers located on rice chromosomes were detected within the pericentric Giemsa-positive heterochromatin of the barley chromosome, indicating that these barley-specific sequences form a block which separates the linkage segments conserved in rice. By our estimate approximately half of the barley-specific sequences of chromosome 5 (1H) show a dispersed distribution, while the other half separates the conserved linkage segments.