* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Foundations of Biology
Medical genetics wikipedia , lookup
Long non-coding RNA wikipedia , lookup
Polymorphism (biology) wikipedia , lookup
Point mutation wikipedia , lookup
Genome evolution wikipedia , lookup
Biology and sexual orientation wikipedia , lookup
Comparative genomic hybridization wikipedia , lookup
Copy-number variation wikipedia , lookup
Designer baby wikipedia , lookup
Site-specific recombinase technology wikipedia , lookup
DNA supercoil wikipedia , lookup
Human genome wikipedia , lookup
Saethre–Chotzen syndrome wikipedia , lookup
Microevolution wikipedia , lookup
No-SCAR (Scarless Cas9 Assisted Recombineering) Genome Editing wikipedia , lookup
Genomic imprinting wikipedia , lookup
Hybrid (biology) wikipedia , lookup
Gene expression programming wikipedia , lookup
Epigenetics of human development wikipedia , lookup
Segmental Duplication on the Human Y Chromosome wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Polycomb Group Proteins and Cancer wikipedia , lookup
Genomic library wikipedia , lookup
Genome (book) wikipedia , lookup
Skewed X-inactivation wikipedia , lookup
Y chromosome wikipedia , lookup
John 15:4 4 Abide in me, and I in you. As the branch cannot bear fruit of itself, except it abide in the vine; no more can ye, except ye abide in me ©2000 Timothy G. Standish From Sequence to Chromosome: The Tip of the X Chromosome of D. Melanogaster Timothy G. Standish, Ph. D. ©2000 Timothy G. Standish The Drosophila Genome 180 million base pairs 120 Mbp has been sequenced The sequenced portion is euchromatin thought to be richer in gene sequences than the remaining heterochromatin Drosophila has a haploid number of 4: 3 autosomes plus 1 sex chromosome Polytene chromosomes can be easily observed in the salivary glands of larvae ©2000 Timothy G. Standish Chromosome Morphology Telomere Distal Arm Proximal Centromere Proximal Stained polytene chromosomes exhibit distinctive banding patterns Arm Distal Telomere ©2000 Timothy G. Standish Chromosome Morphology Telomere Arm Centromere Arm During development chromosome puffs appear which are thought to be correlated with transcriptional activity Telomere ©2000 Timothy G. Standish Naming Chromosome Parts Chromosomes are numbered 1 - 3 X and Y Each chromosome is divided into left (L) and Right (R) arms Arms are divided into numbered divisions going left to right starting with the X chromosome distal left arm and ending with division 100 on the distal right arm of chromosome 3. Divisions are divided into lettered subdivisions going left to right ©2000 Timothy G. Standish Drosophila X Chromosome 2b In division 2b of the X chromosome, a strange bulge appears in images of polytene chromosomes In situ hybridization using cosmid clones mapped to that region show hybridization on the outside of this structure, but not in the middle Figure from http://www.helsinki.fi/~saura/EM/xdiv2.html ©2000 Timothy G. Standish Cosmids A cosmid is a plasmid with the l phage cos site included in it The cos site signals for packaging into l phage, thus the plasmid, including a large insert can be packaged into phage particles without having to waste space on l genes A cosmid combined with a cloned insert cannot exceed the 53 kb limit on how much can be packaged into the l phage head ©2000 Timothy G. Standish An Inverted Repeat May Account For Strange Morphology At X2B 3.5 repeats of satellite-like element 350 bp l l These repeated elements resemble the 1.688 satellite found in units of 1 - 4 on the X chromosome Results indicate that inverted repeats can influence chromosome architecture even when separated by significant distances ©2000 Timothy G. Standish ©2000 Timothy G. Standish ©2000 Timothy G. Standish