Root canal procedure for disarming nonhuman primates.

Nonhuman primates were disarmed by shortening their canine teeth. These teeth were cut off near the gingival level, the entire pulpal tissue removed and the canal filled with a formulated paste which was radiopaque, adhesive and germicidal. The teeth were sealed with a commercial alloy. This endodontic procedure was a quick, practical one-step method for permanently disarming nonhuman primates.     

Relationship of F9 antigen and genes of theT/t complex

Serological studies relating F9 antigen of embryonal carcinoma cells to at the murineT/t complex have been extended and confirm that only the lethal haplotype t¹²- and none of the other five lethal haplotypes-affects the quantitative expression of F9 antigen on sperm. Cytotoxicity tests on preimplantation embryos show that t¹² homozygotes are less susceptible to antiF9 serum than t^w5 homozygotes, and that using specific antimutant haplotype antisera prepared against sperm, t¹² antigen is detectable on morulae, whereas t^w5 antigen is not.     

Mikromorphologie und Orientierungsmuster epicuticularer Wachs-Kristalloide: Ein neues systematisches Merkmal bei Monokotylen

Based on SEM examinations of some 1600 species of monocotyledons out of 61 families the characteristics of their epicuticular waxes are described in this preliminary paper and illustrated by 20 SEM micrographs. Four basic types of waxes are recognized. Two of them occur throughout the monocotyledonous and dicotyledonous orders of angiosperms; two others are of high systematic significance and restricted to particular orders of the monocotyledons: The “Convallaria-Type” is characterized by fine wax platelets with parallel orientation, forming a pattern around the stomata reminiscent of electromagnetic field lines. This type is restricted to the three liliiflorous ordersAsparagales, Liliales, andBurmanniales. The “Strelitzia-Type” is characterized by massive compound wax rodlets; it is restricted to the superordersAreciflorae, Commeliniflorae, Zingiberiflorae, plus the two liliiflorous ordersBromeliales andVelloziales. The data are compared with the classifications ofDahlgren & Clifford (1982); they tentatively indicate the exclusion ofBromeliales, Velloziales, andTyphales from theLiliiflorae.     

Rescue of embryonic cells homozygous for a lethal haplotype of the T/t complex: tw12

A series of recessive mutations which arrest embryonic development are located within the T/t region of chromosome 17 in the mouse. To assess whether these mutations cause death in specific differentiating cells or in all cells of the embryo, we removed the embryonic cells from normal developmental constraints and attempted to grow them ectopically in vivo and in vitro. We have succeeded in producing teratomas and teratocarcinomas by transplantation of inner cell masses from blastocysts of $\text{t}{}^{\mathrm{w12}}\text{+}$ and $\text{t}{}^{\mathrm{w12}}\text{t}{}^{\mathrm{w12}}$ genotypes. The ability of embryonic cells to grow as tumors was not affected by their genotype; 7 of the 17 tumors were homozygous for t^w12, 7 were heterozygous, and 3 could not be analyzed. Virtually all the tumors of both genotypes contained derivatives of all three germ layers. Neuroepithelial and mature nervous tissue was present in all homozygous tumors and all except one heterozygous tumor. However, no cartilage or bone was found in 5 of 5 t^w12 homozygous tumors, while both tissues were present in 3 of 4 t^w12 heterozygous tumors. This observation is compatible with the abnormalities characteristic of $\text{t}{}^{\mathrm{w12}}\text{t}{}^{\mathrm{w12}}$ embryos, which show very localized effects in nervous tissue and more general effects on bone and cartilage formation. Cells derived from homozygous tumors were capable of at least limited growth in culture and a cell line has been derived from one of them. The p63/6.9a marker protein was used to determine the presence of the t^w12 haplotype in the tumor and cultured cells. We conclude that the lethality associated with the t^w12 haplotype is due to lethality of specific cells, and not all cell types.