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Inflorescence Architecture And Flower Sex Ratios In Sagittaria Brevirostra (Alismataceae), Robert B. Kaul
Inflorescence Architecture And Flower Sex Ratios In Sagittaria Brevirostra (Alismataceae), Robert B. Kaul
School of Biological Sciences: Faculty Publications
Two populations of Sagittaria brevirostra from the same lake were sampled 10 years apart and yielded similar data on inflorescence structure and on numbers and ratios of male and female flowers. Larger inflorescences have relatively more male than female flowers than do smaller inflorescences. Pollination success is unrelated to inflorescence size or sex ratio within an inflorescence.
Morphology And Distribution Of Petiolar Nectaries In Ipomoea (Convolvulaceae), Kathleen H. Keeler, Robert B. Kaul
Morphology And Distribution Of Petiolar Nectaries In Ipomoea (Convolvulaceae), Kathleen H. Keeler, Robert B. Kaul
School of Biological Sciences: Faculty Publications
The distribution of petiolar nectaries in 24 species of Ipomoea was investigated. Petiolar nectaries were found on 12 species (8 new reports, 4 confirmations of previous reports) and quoted from the literature as being found on 3 other species; they were absent from 9 species investigated. The structure of petiolar nectaries in the genus ranges from simple beds of superficial nectar-secreting trichomes (1 species), to slightly recessed "basin nectaries" (8 species), to "crypt nectaries," which are structurally the most complex extrafloral nectaries known (3 species). (Structures were not determined for 3 species.) Petiolar nectaries are present in all subgenera, but …
Distribution Of Plants With Extrafloral Nectaries And Ants At Two Elevations In Jamaica, Kathleen H. Keeler
Distribution Of Plants With Extrafloral Nectaries And Ants At Two Elevations In Jamaica, Kathleen H. Keeler
School of Biological Sciences: Faculty Publications
Frequencies of plants with extrafloral nectaries were determined for two elevations in Jamaica. Extrafloral nectaries were found on 0.28 of the plants at sea level (Happy Grove, Portland) and 0.00 of the plants at 1310 m (Whitfield Hall, St. Thomas). Ant abundance, as indicated by discovery of and recruitment to baits, was greater at the lower elevation site. However, despite the apparent absence of plants with extrafloral nectaries, there were abundant ants at 1310 m.
Species With Extrafloral Nectaries In A Temperate Flora (Nebraska), Kathleen H. Keeler
Species With Extrafloral Nectaries In A Temperate Flora (Nebraska), Kathleen H. Keeler
School of Biological Sciences: Faculty Publications
Extrafloral nectaries (EFNs) are glands on a plant, not involved in pollination, that produce solutions containing sugars (and other compounds). Long noted by morphologists, EFNs have recently been observed to be part of ant-plant mutualisms. The function of EFNs appears to be to attract aggressive insects, especially ants, which by disturbing or preying upon herbivores, reduce damage to the plant (Janzen, 1966a,b; Elias and Gelband, 1975; Keeler, 1975, 1977; Bentley, 1976, 1977a,b; Schemske, 1978; Tilman, 1978; Inouye and Taylor, 1979; Pickett ad Clark, 1979). Furthermore, they constitute an unusual plant defense against herbivores: at EFNs plants employ ants as a …
Nocturnal Pollination Of Abronia Fragrans (Nyctaginaceae), Kathleen H. Keeler
Nocturnal Pollination Of Abronia Fragrans (Nyctaginaceae), Kathleen H. Keeler
School of Biological Sciences: Faculty Publications
Abronia fragrans Nutt. (Nyctaginaceae) is a white-flowered herb of dry sandy soils from Idaho and South Dakota to Arizona and Texas. It can be readily observed to fit a night-blooming, moth-pollinated syndrome (Faegri and van der Pijl, The principle of pollination ecology, 1971). This does not seem to have been noted: in all references to A. fragrans we could find, the only indication of nocturnal anthesis was the comment of Nelson (Handbook of Rocky Mountain plants, 1969), who observed that the fragrance was more noticeable at night. Tillett (Brittonia 19:299-327, 1967), working on Pacific species, suggested that the pink …
Neoplastic Transformation Of Epithelial Cells In Whole Mammary Gland In Vitro, Nityanand T. Telang, Mihir R. Benerjee, Anand P. Iyer, Amit B. Kundu
Neoplastic Transformation Of Epithelial Cells In Whole Mammary Gland In Vitro, Nityanand T. Telang, Mihir R. Benerjee, Anand P. Iyer, Amit B. Kundu
School of Biological Sciences: Faculty Publications
Biological characteristics of nodule-like alveolar lesions (NLAL) induced by 7,12-dimethylbenz[a]anthracene (DMBA) in organ culture of whole mammary gland (BALB/c female mice) were assessed after transplantation into gland-free mammary fat pads of syngeneic virgin mice. (i)Tissue- fragment explants from NLAL areas of the gland produced abnormal lobuloalveolar (LA) outgrowths in 3 of 10 fat pads. (ii) Transplantation of dissociated cells of NLAL-derived LA outgrowths into 36 fat pads showed 100% LA outgrowths and 3 (8%) of these 36 outgrowths produced mammary carcinomas. (iii) The explants of dissociated cells from whole mammary glands treated with DMBA …
Glucocorticoid Modulation Of Casein Gene Transcription In Mouse Mammary Gland, Ranjan Ganguly, Nozer M. Mehta, Nivedita Ganguly, M. R. Banerjee
Glucocorticoid Modulation Of Casein Gene Transcription In Mouse Mammary Gland, Ranjan Ganguly, Nozer M. Mehta, Nivedita Ganguly, M. R. Banerjee
School of Biological Sciences: Faculty Publications
The influence of cortisol and prolactin on casein gene expression in the mammary gland of lactating BALB/c mice was measured by using a specific cDNA probe to 15S casein mRNA (cDNAcsn). Casein mRNA (mRNAcsn) level in the mammary gland was decreased by 85% 5 days after adrenal ablation, but then was increased 4.4-fold 12 hr after a single injection of hydrocortisone-21-acetate. An 80% decrease in serum prolactin level, induced by the prolactin inhibitor 2- bromo-α-ergocryptin (CB-154), did not alter the level of mRNAcsn in the gland. Specific transcription of the casein gene in nuclei isolated …