News and Events
  Ensembl release 40
  Writer : Seyeon Weon     Date : 09-24     Hit : 7924    
  트랙백 주소 :
---------- Forwarded message ----------
Ensembl release 40의 announcement가 올려져 있습니다.  원본 announcement에
오타가 있군요.  tenrec인데, tenerec으로 잘못 적혀있군요.  마다가스카르에
사는 고슴도치 비슷한 녀석이군요.  그리고, Stickleback은 우리말로
큰가시고기이군요.  이런 요상한 것들을 왜 막대한 돈을 들여서 sequencing을
하는가 하는 점은 다들 알고 있죠?  한 마디로, genome sequence를 비교를 해서
얻어낼 것이 많을 것이라는 기대이죠.  그런데 왜 하필 이 녀석들인가 하는 점이

tenrec은 "The species were chosen to maximise the branch length of the
evolutionary tree while representing the diversity of mammalian
species."라고 되어 있군요.  현재로서는 가장 일반적인 이유로군요.


"The threespine stickleback Gasterosteus aculeatus offers a unique
biological opportunity for detailed study of the genomic and genetic basis
of species differences in vertebrates. This small marine fish has undergone
one of the most recent and dramatic adaptive radiations on earth.
Sticklebacks normally live in the ocean but migrate into freshwater streams
and lakes every spring to breed. At the end of the last Ice Age, widespread
melting of glaciers led to dramatic changes in sea level and land
elevation. As a result of this global climate change, tens of thousands of
new freshwater lakes and streams were created in formerly ice-covered
regions throughout the Northern hemisphere. Ocean sticklebacks colonized
many of these newly created lakes and streams, and in many cases became
isolated in new environments following the end of widespread melting and
subsequent land elevation. These newly established populations have diverged
over the course of only 10 to 15,000 years in response to different
ecological conditions in each lake and stream, including large differences
water temperature, depth, color, and salinity; food sources; predators; day
length; and seasonal stability of different environments. Thousands of
evolutionary experiments throughout the Northern Hemisphere have since given
rise to new populations of sticklebacks with marked changes in body size,
body shape, feeding specializations, size and pattern of skeletal
structures, presence or absence of defensive armor, salinity tolerance,
temperature preference, parasite resistance, lifespan, and behavior. These
differences are as large as those normally seen between different species or
genuses of animals, and the divergent stickleback types were originally
classified as over 40 different species. Although many of the specialized
forms are known be reproductively isolated even when in contact with each
other (a formal definition of species), the reproductive barriers between
forms are largely either behavior or mechanical. As a result, fully viable
and fertile F1 and F2 hybrids between most forms can be generated using
laboratory matings or in vitro fertilization. The ability to generate
crosses between widely different forms provides an unprecedented opportunity
to use formal genetic analysis to study the number and location of genomic
that underlie evolution of natural species differences in a vertebrate

라고 되어 있군요.  핵심적인 점은 마지막 부분인데, "엄청 다르게 생긴
녀석들끼리 교배가 가능하다는 것"이 주된 이유로군요.  온갖 다양한 이유가 이젠
다 등장을 하는군요.

그리고, 이번 release에서 가장 중요한 점은 Gene Tree라는 것이겠군요.
orthologous relationships을 보기좋게 tree로 그려놓았군요.  orthologous
gene을 정확하게 찾아내는 것은 상당히 까다로운 일이죠.  앞으로 한 동안은
시끌벅절한 일이 될 듯...