River Crossings - Volume 15 - Number 2 - March/April 2006 Volume 15 March/April 2006 Number 2 Daughterless Carp could be reduced or even eliminated from carpbiotech.htm, and is graphically our rivers and lakes. displayed on page 3 of this newsletter. Imagine - rivers and lakes without Asian carp, snakeheads and other invasive Biologists have long known that female Thresher and his group then tested the species. That’s the vision of Ron fish are developed only when an enzyme new gene by injecting it into zebra fish Thresher and his team, a group of called aromatase transforms androgen into eggs and 80% of the brood turned out to scientists conducting “daughterless estrogen. And in the past it had been be male — a striking success given that carp” research at Australia’s Common- possible to chemically block aromatase to some of the daughterless genes are wealth Scientific & Industrial Research produce only males, but Thresher and his inevitably destroyed during the injection Organization (CSIRO) in Hobart as part colleagues have advanced the science by process. Then in 2003 Australia’s of the Australian Invasive Animal figuring out a way to make the trait an Murray-Darling Basin Commission Cooperative Research Center (CRC). inheritable characteristic of future genera- (MDBC) enlisted Thresher and his team Australia faces a major tions. to begin developing the daughterless threat to the health of its carp project that now forms rivers and lakes from an part of MDBC’s 50-year introduced carp much like Native Fish Strategy. we do here in the U.S. And we have been intrigued by The next phase of the project Thresher’s work on daugh- involved creation of a terless carp over the past daughterless line using a few months, and so have small, fast-breeding fish dedicated the first three By blocking the hormone aromatase all carp become males, so over the which becomes sexually articles of this issue of River long term reproduction is reduced and carp population numbers fall. mature in months rather than Crossings to describe his and other fish They first tested the technique on zebra years, allowing scientists to evaluate how genetics work. fish, a cousin of the carp, by locating the (and if) the daughterless gene spreads gene that produces aromatase. They then through the population, generation after In the past we have expressed concerns sequenced that gene in reverse — creating generation. These trials gave Thresher’s about genetic manipulation of biotic a blocker that binds to and neutralizes the group the chance to work out some of the organisms, but these concerns have aromatase gene. An animation of the kinks before beginning work on larger fish centered on the exchange of genetic process can be viewed on-line at: http:// such as carp, which take two years to material between different species and the www.pestanimal.crc.org. au/research/ reach reproductive age. possible creation of the so called “frankenfish”. But in the case of daugh- Inside This Issue terless carp technology this seems unlikely because the genetic work uses Daughterless Carp 1 MO River Water Plan Continues 10 the carp’s own genes to “shut off” a gene FAQs About Daughterless Carp 4 MO Water Diversion Controversy 11 so that females of the species are not Review of Existing Bio-Controls 4 Texas Enviro Water Rights 11 produced. And if this technology can be Asian Carp Bill Advances 6 Climate Change Update 11 used to reduce the numbers of female Greenbelt Defense 7 New River Coordinators 16 carp produced in the wild, it then follows Iowa and Ohio Pollution Problems 8 Meetings of Interest 17 that over the long term carp populations UMR Mussel Concerns 9 Congressional Action 18 1 River Crossings - Volume 15 - Number 2 - March/April 2006 Those kinks include answering the the journal, Ecological Applications. In example, in some species it might be questions: that paper they assess the performance of genetically easier to produce a construct • How many daughterless genes should six different genetic approaches (daugh- that sterilizes females rather than one that the carp carry? terless, male-specific and female-specific converts them to fully functional males. In lethal, sterile constructs, Trojan Genes, fact, Thresher and his team have taken a • Just how many doomsday carp — and etc.) on a modeled carp population in the few small steps to explore this option with how long — will it take to eliminate a wild light of possible effects of different levels medaka. population?; and of (1) environmental variability, (2) • Will the daughterless genes “jump” to demographic factors (e.g. density Once Thresher and his team have opti- other species? dependent population regulation, mized and fully tested the medaka con- complementary harvesting efforts, etc.) structs, they will move on to the more Thresher and his team have now de- and (3) genetic factors (e.g. fitness effects drawn out and logistically more difficult signed, built, and are testing a number of of the construct, gene silencing, etc.). larger fish (i.e. carp). Thresher feels that potential daughterless genetic constructs they are about a year away from producing (i.e. gene manipulations) using Japanese The results of all of their efforts to date a carp construct that they are happy with medaka or ricefish (Oryzias latipes) as the show that daughterless technology is a for testing. And he feels that daughterless test species. Medaka is much smaller than very effective means of population technology will almost certainly be species carp, has a shorter life span or generation control under a wide range of conditions. specific, though he plans to test this time, and is much easier to work with Interestingly, the models also show that directly. He also feels that the carp will under laboratory conditions. To date, under similar conditions, female-specific not revert back to females in later life as neomales (XX males) have been success- lethal and sterility constructs can be as the gene will be inserted into several fully produced in medaka using two efficient as daughterless technology chromosome locations. Even if one copy different constructs, and these fish are itself. Thresher says that this is perhaps fails, it is highly unlikely that all copies now being used for breeding to determine not surprising in retrospect, as both, in a will simultaneously fall down. if the inserted gene has been inherited and sense, are just different means of produc- if the desired characteristics are being ing a daughterless outcome (i.e. heavily Also, he notes that the daughterless carp passed on to the offspring. skewed population sex ratios). For will not be a “frankenfish”. “When we Currently, the CSIRO team is slowly River Crossings working through the genetics of each neomale brood line, and it appears that the Published by constructs are being inherited in at least some lines. This suggests that the Mississippi Interstate Cooperative Resource Association construct has integrated into the chromo- (MICRA) somes, and that some inheritance of the P.O. Box 774 “neomale” condition is occurring. Off- Bettendorf, IA 52722-0774 spring from the different variants of the construct are being compared for fitness MICRA Chairman to see (1) which is the most efficient at Mike Armstrong, Chairman, Arkansas Game and Fish Commission, Little Rock causing the neomale condition, and (2) Executive Board which causes the fewest side effects, etc. Mike Armstrong, Member at Large Once these determinations are made, the Vacant, Vice Chairman “best” fish will be bred and the new data Ron Benjamin, Upper Mississippi River Conservation Committee, Rock Island, IL used to design the next generation of Paul Rister, Lower Mississippi River Conservation Committee, Vicksburg, MS constructs. Steve Adams, Missouri River Natural Resources Committee, Missouri Valley, IA Chris O’Bara, Ohio River Fish Management Team, Parkersburg, WV Pond trials using large indoor, biosecure Bobby Reed, Arkansas River Conservation Committee, Lake Charles, LA aquaria have not yet begun with any of Bill Reeves, Tennessee River Sub-basin Representative, Nashville, TN the medaka constructs, but Thresher Michael Mac, USGS, Biological Resources Division, Columbia, MO hopes to do so within the next six months. Mamie Parker, U.S. Fish and Wildlife Service, Washington, D.C. Timing of these trials will depend on when Coordinator for Large River Activities the team is happy with the construct Jerry L. Rasmussen, U.S. Fish and Wildlife Service, Rock Island, IL proposed for testing and when they have MICRA email: [email protected] sufficient numbers of the desired daugh- MICRA Web Site: http://wwwaux.cerc.cr.usgs.gov/MICRA/ terless carriers in hand to begin an _____________________________________________________________________________ experimental stocking program. River Crossings is a mechanism for communication, information transfer, and coordina- tion between agencies, groups and persons responsible for and/or interested in Meanwhile, they are modeling, in consid- preserving and protecting the aquatic resources of the Mississippi River Drainage erable detail, the likely efficacy and Basin through improved communication and management. Information provided by constraints on the use of daughterless the newsletter, or opinions expressed in it by contributing authors are provided in the and other genetic approaches to manag- spirit of “open communication”, and do not necessarily reflect the position of MICRA ing pest fish populations. This work has or any of its member States or Entities. Any comments related to “River Crossings” recently been submitted for publication in should be directed to the MICRA Chairman. 2 River Crossings - Volume 15 - Number 2 - March/April 2006 build this for carp, it will be from 100 CRC also commissioned a formal survey percent carp genes. We’ll just be rear- two years ago, which assessed public ranging them to achieve what we want,” attitude toward the strengths and he said.