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Recent molecular and morphological systematic investigations revealed that the cacti are most closely related to Anacampseroteae, Portulaca and Talinum of the family Portulacaceae (ACPT clade of suborder Portulacineae). A combined analysis of ndhF, matK, and nad1 sequence data from the chloroplast and the mitochondrial genomes indicates that the tribe Anacampseroteae is the sister group of the family Cactaceae. This clade, together with Portulaca, is well characterized by the presence of axillary hairs or scales. Relationships within Anacampseroteae are characterized by a grade of five species of Grahamia s.l. from North and South America, and Grahamia australiana is found to be sister to the genera Anacampseros and Avonia. A comparison of vegetative characteristics indicates an evolutionary transition from woody subshrubs to dwarf perennial and highly succulent herbs during the diversification of Anacampseroteae. Available evidence from the present investigation as well as from previously published studies suggests that a revised classification of Portulacineae on the basis of inferred phylogenetic relationships might consist of a superfamily that includes Cactaceae and the three genera Anacampseros s.l.(including Avonia and Grahamia s.l.), Portulaca, and Talinum (including Talinella), either referred to three monogeneric families or to a paraphyletic family Portulacaceae*.

An improved in vitro bioassay method for the measurement of LH activity is presented. The method is based on the assay of testosterone produced by "Leydig cell" preparations from mouse testes in the presence of added gonadotrophin. The method is significantly improved in terms of sensitivity, precision and practicability when compared to the previously described bioassay method employing decapsulated testes from adult mice. The sensitivity of the improved method is 15 \g=m\IU for HCG and 50 \g=m\IU for HMG. The useful range of the method is 15\p=n-\260 \g=m\IU for HCG and 50\p=n-\900 \g=m\IU for HMG. Using a 3 + 3 point assay design with each dose in quadruplicate, a mean index of precision ( & # x 0 3 B B ; & # x 0 3 0 5 ; ) of 0.044 was obtained in 19 assays.Human FSH, TSH, ACTH, LTH, STH, oxytocin, vasopressin and LHRH preparations did not influence the bioassay method at levels likely to be found in biological samples. A good correlation was found between estimates obtained by the "Leydig cell" method and by the method using decapsulated testes when various HCG and HMG preparations were used. With the proposed method at least 30 samples can be assayed each week by 2 persons, with a marked reduction in cost. 0 Ford Foundation Fellow in Reproductive Endocrinology.

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