Actinocephalus carrilynnae N. Sp. (Apicomplexa: Eugregarinorida) from the Blue Damselfly, Enallagma civile (Hagen)

ABSTRACT. Actinocephalus carrilynnae , a new species of actinocephalid gregarine, is described from the blue damselfly, Enallagma civile . Trophozoites are unpaired, lying between the host's gut epithelium and peritrophic membrane, and attain a maximum length of at least 1,700 μ m. Protomerites are subspherical. Epimerites are globular, hemispherical with stub-shaped or truncated cone-shaped projections and are attached to the protomerite by means of a fluted stalk. Protomerite-deutomerite length ratio is 0.12 and relatively constant regardless of trophozoite length. Gametocysts are subspherical, 270–280 μ m in diameter, and undergo sporogenesis in 24–36 h, dehiscing by rupture. Spores are biconical, slightly crescent-shaped, and very uniform in size: 15 μ m long and 4–5 μ m wide. The parasite infects both adult and naiad hosts.     

A neontological interpretation of conodont elements based on agnathan cyclostome tooth structire function, and development

Krejsa, R. J., Bringas, P. Jr. & Slavkin, H. C. 1990 10 15: A neontological interpretation of conodont elements based on agnathan cyclostome tooth structure, function, and development. Lethaia , Vol. 23, pp. 359–378. Oslo. ISSN 0024–1164.
Speculation about a conodont-cyclostome connection has led us to search for and establish a biological basis for various characteristic structures in conodont elements. Measurements of juvenile hagfish palatal and lingual teeth overlap those of representative conodont elements, demonstrating a size correspondence of conodonts with teeth of living vertebrates. When hagfish tooth histology is compared with internal and surface topography (SEM) of hagfish, keratinous teeth and mineralized conodont elements, microspaces and tubules similar to those found in hagfish functional tooth coverings and replacement elements are also found within the white matter' of conodont elements. It is provisionally suggested that the primary organic matrix of conodont elements could be keratin and/or keratin-related molecules, and that individual conodont elements could represent shed tooth coverings. The basal bodies' found in certain conodont elements could be replacement elements. These interpretations are contrary to several paradigms of orthodox conodontology. ▭ Agnatha, conodonts, cyclostomes, hagfish, keratin, paleo-biology, shedding, teeth .     

RNA and Protein Synthesis in Germinating Pine Pollen

The results of autoradiographic experiments demonstrate that,as with the pollen of most other species, both the generativeand vegetative nuclei of Loblolly Pine (Pinus taeda) activelyengage in RNA synthesis from the very early stages of pollengermination. Unlike most other species, however, this newlysynthesized RNA includes rRNA. Evidence is provided for theimportance of this newly synthesized RNA in the process of continuedpollen tube growth. One and two-dimensional gel electrophoretic analysis revealsa number of both qualitative and quantitative differences amongthe proteins synthesized during the early stages of germinationand the later stages of pollen tube growth. One of the mostnotable of these is a 36 kD protein, the synthesis of whichpredominates during the later stages of pollen germination.A similar pattern of 36 kD protein synthesis is observed whenmRNA extracted from pollen at each of these stages is translatedin vitro. Key words: Pinus, pollen tube growth     

Evolution of the Adh locus in the Drosophila willistoni group: the loss of an intron, and shift in codon usage

We report here the DNA sequence of the alcohol dehydrogenase gene (Adh) cloned from Drosophila willistoni. The three major findings are as follows: (1) Relative to all other Adh genes known from Drosophila, D. willistoni Adh has the last intron precisely deleted; PCR directly from total genomic DNA indicates that the deletion exists in all members of the willistoni group but not in any other group, including the closely related saltans group. Otherwise the structure and predicted protein are very similar to those of other species. (2) There is a significant shift in codon usage, especially compared with that in D. melanogaster Adh. The most striking shift is from C to U in the wobble position (both third and first position). Unlike the codon-usage-bias pattern typical of highly biased genes in D. melanogaster, including Adh, D. willistoni has nearly 50% G + C in the third position. (3) The phylogenetic information provided by this new sequence is in agreement with almost all other molecular and morphological data, in placing the obscura group closer to the melanogaster group, with the willistoni group farther distant but still clearly within the subgenus Sophophora.      

ACTION SPECTRA OF PHOTOMORPHOGENIC INDUCTION AND PHOTOINACTIVATION OF GERMINATION IN ARABIDOPSIS THALIANA

Detailed action spectra for photoinduction and photoinactivationof germination of the crucifer, Arabidopsis thaliana, have beendetermined. The photoresponse has a typical red, far-red sensitivitywith a peak susceptivity for induction at 660 mµ and twomaxima at 720 and 740 mµ for inactivation. The responsecurve for induction is a logarithmic function of dose and forinactivation a linear function of dose. The close similarity of the action spectra with other photomorphogenicaction spectra in diverse plant tissues indicates that thereis little attenuation by screening pigments or scattering beforethe photoreceptor is reached. The low dark germination percentageand the reproducible light sensitivity make the system advantageousfor the study of photoimetic substances. (Received October 1, 1960; )     

Life stage‐dependent effects of experimental heat waves on an insect herbivore

1. Worldwide concern about the consequences of climate change has prompted efforts to understand and predict the responses of populations to changes in temperature. 2. A heat wave can adversely affect organisms, may affect different life stages differently, and could decrease populations. In this study, green peach aphid [Myzus persicae (Sulzer)] nymphs, reproductive adults, and late‐reproductive adults were exposed to a heat wave, defined as 5 °C above the control temperature regime for five consecutive days. 3. The negative effects of experimental warming on development, reproduction, and survival negatively affected population growth. Nymphs and reproductive adults were more severely impacted than late‐reproductive adults. 4. Experiments designed to mimic temperature regimes can assess the direct effects of climate change on individuals and populations. Our study highlights the importance of assessing the life stage‐specific responses to heat stress.     

Microbiological quality of tomato (<i>Solanum lycopersicum</i> L.) produced under greenhouse conditions in five Municipalities of the State of Mexico

The aim of the current research was to determine tomato (Solanum lycopersicum L.) microbiological quality produced under greenhouse conditions in 5 municipalities of the State of Mexico. Studies were conducted during the 2013 production cycle to know the risks and apply prevention strategies prior to its consumption. A microbiological analysis of samples of irrigation water, soil and 100 tomato fruits variety cid was performed to determine Aerobic Mesophiles, Total Coliforms and Fecal Coliforms. The methodology used were those according to the Official Mexican Standards NOM- 109-SSA1-1994, NOM-110-SSA1-1994, NOM-092-SSA1-1994, NOM-113-SSA1-1994, and the Regulations of the National French Organization for Standardization (AFNOR) NF V08-60, and NOM-093-SSA1-1994, which establish the allowable limits for the study microorganisms. The results showed a zero level of pollution in water and soil samples. For fruits, levels of Aerobic Mesophilic were within the maximum limits permitted by the standards. The municipality of Texcaltitlan showed the highest average for these microorganisms (10083.80 CFU/mL). Huixquilucan showed 2266.84 CFU/mL for Total Coliforms. For Fecal Coliforms, municipalities of Coatepec and Texcaltitlan exceeded the allowed limit.