Variation in heat shock proteins within tropical and desert species of poeciliid fishes

The 70-kilodalton heat shock protein (hsp70) family of molecular chaperones, which contains both stress-inducible and normally abundant constitutive members, is highly conserved across distantly related taxa. Analysis of this protein family in individuals from an outbred population of tropical topminnows, Poeciliopsis gracilis, showed that while constitutive hsp70 family members showed no variation in protein isoforms, inducibly synthesized hsp70 was polymorphic. Several species of Poeciliopsis adapted to desert environments exhibited lower levels of inducible hsp70 polymorphism than the tropical species, but constitutive forms were identical to those in P. gracilis, as they were in the confamilial species Gambusia affinis. These differences suggest that inducible and constitutive members of this family are under different evolutionary constraints and may indicate differences in their function within the cell. Also, northern desert species of Poeciliopsis synthesize a subset of the inducible hsp70 isoforms seen in tropical species. This distribution supports the theory that ancestral tropical fish migrated northward and colonized desert streams; the subsequent decrease in variation of inducible hsp70 may have been due to genetic drift or a consequence of adaptation to the desert environment. Higher levels of variability were found when the 30- kilodalton heat shock protein (hsp30) family was analyzed within different strains of two desert species of Poeciliopsis and also in wild-caught individuals of Gambusia affinis. In both cases the distribution of hsp30 isoform diversity was similar to that seen previously with allozyme polymorphisms.      

Studies in African Cyperaceae 20. New taxa and combinations in Pycreus Beau v.

One new species, five new subspecies and one variety of the genus Pycreus , are described from East Africa, viz. Pycreus micromelas Lye, P. sanguinolenlus (Vahl) Nees ssp. nairobiensis Lye, P. longistolon Kükenthal ssp. airofusca Lye, P. lanceolatus (Poiret) C. B. Clarke ssp. ugandensis Lye, P. flavescens (L.) Reichenb. ssp. laevinux Lye, P. flavescens (L.) Reichenb. ssp. microglumis Lye, and P. flavescens (L.) Reichenb. var. castaneus Lye.
In addition eight new combinations are made, viz. P. alms (Turrill) Lye, P. af–rozonatus Lye, P. niger (Ruiz & Pavon) Cufod. ssp. elegantulus (Steudel) Lye, P. macrostachyos (Lam.) J. Raynal ssp. tremulus (Poiret) Lye, P. flavescens (L.) Reichenb. ssp.fallaciosus (Cherm.) Lye, P. flavescens (L.) Reichenb. ssp. intermedius (Steudel) Lye, and P. flavescens (L.) Reichenb. ssp. tanaënsis (Kükenthal) Lye.     

Studies in African Cyperaceae 21. New taxa and combinations in Kyllinga Rottb.

Eight new species, one new subspecies and one new variety of Kyllinga are described from tropical Africa, viz. Kyllinga brunneoalba Lye, K. afropumila Lye, K, albogracilis Lye, K. aureovillosa Lye, K. alba–purpurea Lye, K. rhizomafragilis Lye, K. microbracleata Lye, K. afro–occidentalis Lye, K. erecta Schumacher ssp. albescens Lye, and K. melanosperma Nees var. hexalata Lye. In addition nine new combinations are made, viz. Kyllinga peteri (Kükenthal) Lye, K. bigibbosa (Fosberg) Lye, K. odorata Vahl ssp. appendiculata (K. Schum.) Lye, K. alba Nees ssp. ascolepidioides (H. Cherm.) Lye, K. nervosa Steudel ssp.flava (C.B.C1.) Lye, K. melanosperma Nees ssp. elata (Steudel) Lye, K. brevifolia Rottb. ssp. lurida (Kükenthal) Lye, K. bre–vifolia Rottb. ssp. intricata (H. Cherm.) Lye, and K. comosipes (Mattf. & Kükenthal) Agnew & Hanid ssp. decolorans (Kükenthal) Lye.     

Studies in African Cyperaceae 19. The genera Anosporum Nees and Sorostachys Steudel

The two genera Anosporum Nees and Sorostachys Steudel, both with a congested inflorescence and an eucyperoid culm– and leaf–anatomy, are reestablished. They have previously been placed in Cyperus s.l. Anosporum contains three distinct species, two of which are found in Africa. Sorostachys contains two species, one of which is found in Africa. Three new combinations are made, viz. Anosporum pec–tinatus (Vahl) K. Lye, Sorostachys pulchellus (R.Br.) K. Lye, and S. leucocephalus (Retz.) K. Lye.     

Stimulation of ovine myometrial activity by 6-keto prostaglandin E1

6-keto prostaglandin E₁ (6KE) is a metabolite of PGI₂, which we have shown previously inhibits spontaneous myometrial activity. In the present study we examined the effects of 6KE on uterine electrical and mechanical activity in non-pregnant ovariectomized sheep. 6KE stimulated uterine activity in a dose-dependent fashion. The effect was enhanced by pre-treatment with estradiol (E2). It was not influenced by pre-treatment with meclofenamic acid and was not associated with significant changes in the concentrations of 13,14 dihydro 15-keto PGF_2α in vena cava plasma. After E2 treatment, 6KE had 0.2–0.3 of the stimulatory activity of PGF_2α. In the absence of E2, the uterine response to both 6KE and PGF_2α was decreased. In animals in which spontaneous myometrial activity was inhibited by PGI2, the uterus remained responsive to 6KE. We conclude that in the ovariectomized non-pregnant sheep 6KE stimulates uterine activity, and that the effect is independent of endogenous PG production.     

Studies in African Cyperaceae 24. New taxa and combinations in Ascolepis and Isolepis

One new species, three new subspecies and two new varieties of Ascolepis Steudel and one new species of Isolepis R. Br. are described from East Africa, viz. Ascolepis lineariglumis Lye, A. lineariglumis Lye var. pulcherrima Lye, A. protea Welw. ssp. rhizomatosa Lye, A. protea Welw. ssp. atropurpurea Lye, A. protea Welw. ssp. chrysocephala Lye, A. pusilla Ridley var. microcuspis Lye, and Isolepis keniaensis Lye. Two new combinations are made, viz. Ascolepis protea Welw. ssp. anthemiflora (Welw.) Lye and A. protea Welw. ssp. bellidiflora (Welw.) Lye.     

Studies in African Cyperaceae 23. New taxa and combinations in Fimbristylis Vahl II

Two new subspecies, Fimbristylis miliacea (L.) Vahl ssp. pallescens Lye and F. miliacea (L.) Vahl ssp. macroglumis Lye, are described and illustrated from East Africa. In addition two new combinations are made, viz. F. complanata (Retzius) Link ssp. keniaeensis (Kükenthal) Lye and F. ferruginea (L.) Vahl ssp. sieberiana (Kunth) Lye.