Document x5m764qyw21DJYEKxYrk3NXmQ

27-CV-10-28862 Table 2. Size (standard length, millimeters) of adult male platyfish with different genotypes. pepc pcp i p ip i Birth date Y-Ir Y-Ir Mean Range N Y-Ir Y-Br Mean Range Y-Br Y-Br N Mean Range N 2/27/71 28 Pedigree 2828 1 32 30-34 4 6/25/71 24.5 9/30/71 22.1 23-26 19-25 Pedigree 2918 2 31 28-33.5 6 5 27.3 24.5-30 2 2/15/72 25 3/17/72 22.7 Pedigree 3030 1 29.3 28.5-31 21-23.5 8 27.4 27-29 3 4 9/20/71 10/20/71 1/26/72 a 1/26/72b X -Y -I, Pedigree 2964 30.5 29.5-31 3 36.6 35-38 3 25.5 22.5-27 3 31.8 28-34.5 5 25.8 24-28 6 28.3 24.5-32 6 24.1 22-26 6 29 27.5-30.5 6 X-Y-Br 11/1/71 24.7 23-26.5 13 Pedigree 2974 29.9 27.5-32 15 Filed in Fourth Judicial District Court 11/17/2017 6:21 PM Hennepn>C dffl& iiMN completely in breeding structure and appearance. The P locus of X. maculatus is of general significance not only for pitui tary gland function in teleosts, but for all vertebrates including man. This' system may become an important model for studying the genetic control of endocrine structure and function. K laus D. K allman Osborn Laboratories of Marine Sciences, New York Aquarium, New York Zoological Society, Brooklyn 11224 M artin P. Schreibman Brooklyn College of City University of New York, Brooklyn 11210 Valerie Borkoski Osborn Laboratories of Marine Sciences, New York Aquarium P l may specify two proteins differing in their efficiency in initiating morphogenic changes. The P locus probably exerts its effect directly on the pitui tary gland, although the role of the hypothalamus should also be evaluated. The P gene also has an indirect ef fect on the adult size of male platyfish. Since growth rate decreases with in creasing androgen production (9), early maturing males are significantly smaller than late maturing ones. Size differ ences between the two classes of males were absolute within seven broods, whereas in one (9/30/71) the largest lrlr male surpassed the smallest IrBr male by 0.5 mm (Table 2). The ex ceptional BrBr male (2964-11) that matured at 18 weeks (Table 1), is also the smallest homozygous Br male obtained so far. Small and large fish grow at the same rate, but the former stop at an earlier age when they be come sexually mature. Since these ob servations did not differ throughout the year, natural daylight, which was not controlled, cannot account for the differences in growth and age of sexual maturity. The P factors have manifested them selves both in the offspring of intraand interstrain crosses. This poly morphism is a natural component of wild populations and is apparently widespread. We have found it in platy fish stocks collected from four river sys tems {10). The sex chromosome con stitution of the males, XY or YY, has nothing to do with adult size and age of sexual maturation. Pe and Pl can be both X- and Y-linked. An X chromo some with Pl has recently been identi fied from the Belize population {10). 680 Similar variations in size and age of sexual maturation have been re ported for a number of other species of Xiphophorus {11), but little is known about the genetics of these dif ferences. The polymorphism at this locus may have been important for the evolution of the genus, since various body parts show allometric growth and large males, for example, those of X. pygmaeus, not only assume a different habitus, but also develop structures not present in the smaller morphs {12). The allele for early gonadotrop differentiation has become fixed in X. pygmaeus pygmaeus inhabiting the Rio Axtla, and has led to a uniform popu lation of small males. However, X. pygmaeus nigrensis in the Rio Choy is polymorphic at the P locus resulting in two kinds of males {13). Elmination of Pe from the Rio Choy would leave two populations: X. pygmaeus pygmaeus homozygous for Pe (small size) and X. pygmaeus nigrensis ho- References and Notes 1. K. D. Kallman, Zoologica New York 55, 1 (1970) . 2. Xiphophorus maculatus is polymorphic for sex chromosomes. Three kinds of females (XX, WX, WY) and two kinds of males (XY, YY) may occur within the same natural population. YY males are not the result of special laboratory crosses as are the YY males of the rice fish, Oryzias latipes [T. Yamamoto, Genetics 50, 45 (1964)]. 3. V. L. de Vlaming, / . F ish Biol. 4, 131 (1972). 4. M. Gordon, The Care and Breeding of Laboratory Animals, F.. J. Farris, Ed. (Wiley. New York, 1950), p. 345. 5. K. D. Kallman, Zoologica New York 50, 151 (1965). 6. C. Grobstein, Univ. Calif. Publ. Zool. 47, 1 (1940); / . Exp. Zool. 109, 215 (1948). 7. G. Pickford and J. W. Atz, The Physiology of the Pituitary Gland of Fishes (New York Zoological Society, New York, 1957). 8. M. P. Schreibman, Zoologica New York 49. 217 (1964). 9. H . Cohen, ib id . 31, 121 (1946). 10. K. D. Kallman and M. P. Schreibman, unpublished results, 11. K. D. Kallman, Zoologica New York 56, 77 (1971); -------- and R. Borowsky, H ered ity 28, 297 (1972); G. Peters, Z. Zool. Syst. Evolu tions Forsch. 2, 185 (1964); C. D. Zander, Z. Vererbungsl. 96, 128 (1965). 12. D. E. Rosen, Bull. Fla. State Mus. Biol. Ser. 5, 57 (1960). 13. K. D. Kallman, unpublished results. 14. Supported in part by NIH grant 5 ROl CA06665. 1 January 1973; revised 5 April 1973 Perfluorocarbons Having a Short Dwell Time in the Liver Abstract. Perfluorinated organic liquids are useful as high capacity oxygen and carbon dioxide solvents. After intravenous infusion most of these perfluori nated emulsions are deposited in the liver and spleen in a matter of days, where they remain for the lifetime of the animal. Hence, while they may be useful as isolated organ perfusion media their value as artificial blood is limited. A family of perfluorocarbons has now been discovered, which, although deposited in the liver after circulation in the blood, leave the liver to be excreted via the lungs and skin in a matter of days without apparent harm to the animal. Since 1966, when organic liquid breathing was first reported, there have been over 100 publications concerning the use of inert fluorochemicals {!) in physiological research. These include reports of liquid breathing (2), of organ perfusion (5), of infusion in whole animals (4), and as radiographic SCIENCE, VOL. 181