19 research outputs found
Large Tandem, Higher Order Repeats and Regularly Dispersed Repeat Units Contribute Substantially to Divergence Between Human and Chimpanzee Y Chromosomes
Comparison of human and chimpanzee genomes has received much attention,
because of paramount role for understanding evolutionary step distinguishing us
from our closest living relative. In order to contribute to insight into Y
chromosome evolutionary history, we study and compare tandems, higher order
repeats (HORs), and regularly dispersed repeats in human and chimpanzee Y
chromosome contigs, using robust Global Repeat Map algorithm. We find a new
type of long-range acceleration, human-accelerated HOR regions. In peripheral
domains of 35mer human alphoid HORs, we find riddled features with ten
additional repeat monomers. In chimpanzee, we identify 30mer alphoid HOR. We
construct alphoid HOR schemes showing significant human-chimpanzee difference,
revealing rapid evolution after human-chimpanzee separation. We identify and
analyze over 20 large repeat units, most of them reported here for the first
time as: chimpanzee and human ~1.6 kb 3mer secondary repeat unit (SRU) and
~23.5 kb tertiary repeat unit (~0.55 kb primary repeat unit, PRU); human 10848,
15775, 20309, 60910, and 72140 bp PRUs; human 3mer SRU (~2.4 kb PRU); 715mer
and 1123mer SRUs (5mer PRU); chimpanzee 5096, 10762, 10853, 60523 bp PRUs; and
chimpanzee 64624 bp SRU (10853 bp PRU). We show that substantial
human-chimpanzee differences are concentrated in large repeat structures, at
the level of as much as ~70% divergence, sizably exceeding previous numerical
estimates for some selected noncoding sequences. Smeared over the whole
sequenced assembly (25 Mb) this gives ~14% human--chimpanzee divergence. This
is significantly higher estimate of divergence between human and chimpanzee
than previous estimates.Comment: 22 pages, 7 figures, 12 tables. Published in Journal of Molecular
Evolutio
A Validation and Generality Study of the Committed Action Questionnaire in a Swedish Sample with Chronic Pain
Characterization and defining of a core set of novel microsatellite markers for use in genotyping and diversity study of Adriatic fig (Ficus carica L.) germplasm
Heterogeneous Nature and Distribution of Interruptions in Dinucleotides May Indicate the Existence of Biased Substitutions Underlying Microsatellite Evolution
Polarisation vision in ants, bees and wasps
We review here what is known from behavioural, anatomical and physiological studies about polarisation sensitivity in the hymenopteran insect groups of ants, wasps and bees. We briefly summarise the behavioural evidence for the use of polarised skylight in orientation and navigation, including some lesser known or less accessible older work, and then review our state of knowledge of the polarisation sensitivity and the arrangement of photoreceptors in compound eyes and in ocelli. We note in particular how little we know about the role of ocelli in polarisation vision.20 page(s