Drosophila melanogaster subgroup Drosophila melanogaster - cosmopolitan Drosophila simulans - cosmopolitan Drosophila mauritiana - Mauritius Drosophila sechellia - Seychelles Drosophila yakuba - Equatorial Africa Drosophila santomea - Sao Tome Drosophila teissieri - Equatorial Africa Drosophila erecta - Central West Africa Drosophila orena - Cameroons
mel f x sim m sim f x mel m Viable, sterile f Viable, sterile m Larval lethal m Embryo lethal f aabb AAbb x aaBB AaBb Hmr allele of melanogaster (transcription factor) Lhr allele of simulans (chromatin binding protein)
“Eventually, the story of the chromosomal mechanisms and its evolution will have to be entirely rewritten in molecular terms.” Michael White, 1973, Animal Cytology & Evolution, 2nd edition.
Paracentric inversions are the most common rearrangement Segregating in 106 out 183 species. - 57% - (Powell 1997). inversions have become fixed during the evolution of the genus (Clayton & Guest 1986).
a b c d e f g h i j k l m n o p q r s t a b j i h g f e d c k l m n o p q r s t a b j l o n m l k c d e f h i p q r s t a b c d e f g h i j k l m n o p q r s t a b c d e f g h i o n m l k j p q r s t a b k l m n o i h g f e d c j p q r s t
12 genomes have been sequenced in the genus Drosophila
( Cáceres et al. Science 1999 ) Ectopic recombination between homologous fragments of DNA
centromeretelomere 3R of D. melanogaster centromeretelomere 3R of D. simulans BACs 84F193F6-7 BACR07M14 BACR45A07 BACR16N15 BACR42I20 BACR08K01 ~280 Kb ~450 Kb
Inversion-mediated duplications can result from staggered isochromatid breaks & repair. 5' 3' 5' 3' 5' 3' 5' 3' 5' 3' 5' 3'5' 3' 5' 3' 5' AB C DE 3' 5' 3' 5' 3' ABCDIJKEFGBCDIH
Lemeunier & Ashburner, 1976
BLAST-N of D. mel 3R transcripts against D. yak 3R J. Ranz, C. Bergman & M. Ashburner
Flanking duplications are a common by-product of the genome reorganization between D. melanogaster and D. yakuba. withwithout 209
outgroup species D. yakubaD. melanogaster Most inversions occurred in the D. yakuba lineage A-B A]-----[BA-B A]-----[B 28 ( 96.6 % )1 ( 3.4 % ) 1: 2:
Large-scale comparison of the gene order between D. melanogaster and D. yakuba. Breakpoints Mb Myr Mb Myr breakpoints = inversions
Cluster gram based on the number of breakpoints that correspond to inversions
Genes within genes within genes
Number of antisense/sense overlapping pairs of genes in D. melanogaster
D. melanogaster is different from H. sapiens. RIKEN Group and FANTOM Consortium, Antisense transcription in the mammalian transcriptome. Science (5740)
Thanks to: Jose Ranz (Cambridge). Casey Bergman (Manchester). Marcin von Grotthuss (Cambridge). Karen Eilbeck & Suzi Lewis (Berkeley). Lincoln Stein (CSGL) & Richard Durbin (WTGC) Hadi Quesneville (Paris). The MRC for 25 years of continuous funding. The BBSRC for a grant to Jose. EMBO for support to Marcin. The Royal Society for a Fellowship to Casey.
Annotated genome Annotation Depth of knowledge Breadth of knowledge Detailed analysis (typically biological) of single genes Large-scale analysis (typically computational) of entire genome
Assemblies from the 12 ongoing Drosophila sequencing projects are available right now