filter  sets  from  ten  different  tissues  each  composed  of 18,000 clones. These libraries are derived from whole body tissue, spleen, gill, gut, gonad, brain, eye, liver, kidney, and from mixed tissues. They have an average insert size of 1 kb. Limited  amounts  of  RNA  can  be  obtained  upon  re- quest.  Incyte  Genomics  will  supply  a  BAC  library  with 40,000 clones, with an average insert size of 120 kb equiva- lent to 10× genome coverage as gridded filter sets. Collabo- rators  can  request  limited  sequence  scanning  of  cosmids and BACs from the Fugu Genomics Group. Contacts Dr.  Greg  Elgar  (Group  Leader):  gelgar@hgmp.mrc. ac.uk;  and  Dr.  Melody  Clark  (Senior  Postdoctoral  Associ- ate):  mclark@hgmp.mrc.ac.uk,  HGMP  Resource  Centre, Wellcome  Genome  Campus,  Hinxton,  Cambridge,  CB10 1SB: UK. Telephone: 44 1223 494562; fax: 44 1223 494512; Web site: http://fugu.hgmp.mrc.ac.uk/ The contact for clones and materials: Distributive Ser- vices  at  the  HGMP:  http://www.hgmp.mrc.ac.uk/Biology/; B.  Gorick  in  the  Distributed  Services  Group:  bgorick@ hgmp.mrc.ac.uk; Incyte Genomics: http://www.incyte.com/ JAPANESE  MEDAKA  (ORYZIAS   LATIPES) RESOURCES   IN  JAPAN Program  Description:  Nagoya  University Resources Maintenance of freshwater fish stocks at Nagoya University, Japan,  began  with  the  medaka  d-rR  strain  generated  by Tokio  Yamamoto  in  the  middle  1940s.  In  this  strain,  the females are white and the males are orange–red. Yamamoto was  the  first  to  demonstrate  sex  reversal  in  fish  using  this strain. The medaka d-rR strain is widely used for studies on sex  differentiation  and  in  testing  for  endocrine  disrupting compounds. In the 1960s his successor, Hideo Tomita, col- lected about 80 spontaneous mutants of the medaka, most of which are recessive and viable. About 60% of them are color mutants. Others are morphological mutants including Da  and  el;  studies  of  the  positional  cloning  of  genes  pro- ducing the mutant condition are underway. Based on these researches, the Laboratory of Freshwa- ter Fish Stocks was established in 1981. The stock center has fish  rooms  with  500  aquaria  kept  at  26°C,  and  an  800-ha outdoor farm with 400 aquaria. Husbandry and breeding of the  fish  is  automated.  About  120  strains  are  maintained, including  original  spontaneous  mutants,  strains  produced from them, and some green fluorescent protein-transgenic lines.  The  fish  are  distributed  to  laboratories  worldwide. The comprehensive Medaka Home Page (see below) main- tained by the Nagoya laboratory provides online informa- tion  for  scientists.  There  are  data  on  the  medaka’s  basic biology,  phylogeny,  genetics,  embryology,  and  physiology, as  well  as  information  on  its  use  in  neurobiology,  cancer research,  and  in  detecting  endocrine  disruptors  in  the  en- vironment. The  most  important  activity  of  the  laboratory  is  in developing new technologies for fish experiments, particu- larly nuclear-transplantation techniques to use with diploid fish (Wakamatsu et al., 2001). Cryopreservation of diploid embryos is difficult because fish eggs contain a large volume of yolk. However, diploid fish can be produced in one gen- eration by nuclear transplantation of cryopreserved embry- onic cells, a method that is more efficient than using frozen sperm.  The  latter  method  requires  a  few  generations  to obtain  diploid  individuals.  Nuclear  transplantation  of  cul- tured cells carrying foreign genes may allow the production of genetically modified strains. Services The  laboratory  supplies  medaka  embryos  to  research- ers.  They  are  packed  in  test  tubes  and  sent  by  rapid  mail. Available  strains  are  listed  in  the  Web  site  and  in  Tomita (1992). Contact Dr. Yuko Wakamatsu, Bioscience Center, Nagoya Uni- versity, Furocho, Chikusaku, Nagoya 464-8601, Japan. Tele- phone:   81-52-789-4294;   fax:   81-52-789-5053;   e-mail: wakamatu@bioll.bio.nagoya-u.ac.jp;  Web  site:  Medaka Home Page http://bioll.bio.nagoya-u.ac.jp:8000/ Program  Description:  The  University  of Tokyo Resources Since  1985,  Akihiro  Shima,  Atsuko  Shimada,  and  Shizuko Takada  have  maintained  over  80  wild  populations  of  the Japanese  medaka  (Oryzias  latipes)  with  support  from  the Ministry of Education, Science, Sports, and Culture, Japan. Preserving these medaka strains as gene resources has been their primary goal, but recently, studies were begun to fur- ther  characterize  the  medaka  as  a  useful  laboratory  model for biomedical research. A nonmammalian test system for assessing  germ-cell  mutagenesis  induced  by  radiation  or Fish Resource Centers S241 Next >>