A rapid,single leaf,nucleic acid assay for determining the cytoplasmic organelle complement of rapeseed and related Brassica species

Summary An assay is described whereby Eco RI restriction fragment length polymorphisms of mitochondrial and chloroplast DNAs can definitively identify cytoplasms of interest in Brassica crop development. Restrictable mitochondrial and chloroplast DNA is extracted from as little as 2–3 g and 0.5 g leaf tissue, respectively, and the donor plants are able to continue to develop in a normal manner. An unknown cytoplasm can be identified in three days, which is a considerable saving in time and labor compared to the several years required by traditional methods. The assay is very inexpensive and should be established as a routine procedure in laboratories involved in sexual or somatic Brassica hybrid production.     

Starvation and the Mating Success of Wild Male Mediterranean Fruit Flies (Diptera: Tephritidae)

Recent evidence suggests that the nutritional state of male Mediterranean fruit flies, Ceratitis capitata (Wied.) (medfly), is an important influence on various components of their reproductive biology, including mating success. The objective of the present study was to examine experimentally the effect of temporary starvation on the mating success of wild male C. capitata. Males were maintained on protein–sugar or sugar-only diets, and for each diet we compared the mating success of continuously fed males versus males starved for 18 or 24 h immediately before testing. In trials conducted on field-caged, host trees, males starved for 24 h obtained only about half as many matings as fed males for both diets. However, when the starvation period was 18 h, starved males reared on the protein–sugar diet mated significantly less frequently than fed males, whereas starved males reared on sugar mated as often as fed males. Measurements of male pheromone calling and female attraction revealed that reduced mating success likely reflected the decreased signaling activity of starved males.     

Measuring sexual selection on females in sex‐role‐reversed Mormon crickets (Anabrus simplex,Orthoptera: Tettigoniidae)

Although many studies examine the form of sexual selection in males, studies characterizing this selection in females remain sparse. Sexual selection on females is predicted for sex‐role‐reversed Mormon crickets, Anabrus simplex, where males are choosy of mates and nutrient‐deprived females compete for matings and nutritious nuptial gifts. We used selection analyses to describe the strength and form of sexual selection on female morphology. There was no positive linear sexual selection on the female body size traits predicted to be associated with male preferences and female competition. Instead, we detected selection for decreasing head width and mandible length, with stabilizing selection as the dominant form of nonlinear selection. Additionally, we tested the validity of a commonly used instantaneous measure of mating success by comparing selection results with those determined using cumulative mating rate. The two fitness measures yielded similar patterns of selection, supporting the common sampling method comparing mated and unmated fractions.     

Determination of adenosine triphosphate in human semen to estimate the fertilizing potential and to quantify sperm antibodies

The measurement of the ATP content of fresh semen is as accurate as the estimation of sperm motility by conventional methods in discriminating between semen of fertile versus subfertile men. The ATP content of frozen thawed donor semen is correlated with the probability of conception per cycle of insemination. Exact quantification of cytotoxic sperm antibodies in serum is possible with the adenosine-triphosphate-release-cytotoxicity test, since measurement is free of the bias of microscopic examination. The procedure has been simplified by testing only one serum dilution and calculating the ‘sperm toxicity index’.     

Molecular cloning and physical characterization of a Brassica linear mitochondrial plasmid

Summary A linear mitochondrial plasmid reported to be associated with cytoplasmic male sterility in the genus Brassica was analyzed. A protein was found to be associated with the 5 ends of the plasmid. The entire plasmid was cloned by the homopolymer tailing technique via free hydroxyl groups present at its 3 ends. DNA sequence analysis of the cloned plasmid revealed a perfect terminal inverted repeat of 325 base pairs. Southern hybridization and restriction enzyme mapping analysis confirmed colinearity of the native plasmid and the clone, which showed significant homology with organelle DNA but not with nuclear DNA. Under high-stringency hybridization conditions, an internal 4.6 kb fragment of the 11.5 kb plasmid hybridized to the main mitochondrial genome in several species. Although the hybridization signal was weaker, the chloroplast genome also showed homology to the mitochondrial plasmid. The plasmid was undetectable at a molar ratio of less than 1/10 000 of the main mitochondrial genome in some lines of Brassica and Raphanus that contain the Ogura male sterile cytoplasm (cms). The absence of the plasmid in these sterile lines demonstrates that the plasmid is not required for the expression and maternal inheritance of male sterility.     

No evidence for a pleiotropic relationship between male sterility and cyanide-resistant respiration in Plantago lanceolata

Gynodioecy, the coexistence of hermaphrodites and male steriles, is frequent in populations of Plantago lanceolata L. A condition for the maintenance of gynodioecy in an obligatory outbreeding species like this is an increase in female fitness in male steriles compared with hermaphrodites. One of the possible underlying mechanisms, a lower cyanide-resistant respiration in male steriles, which could lead to a higher metabolic efficiency, was investigated. For the experiments adult plants were used, because the effects which compensate for male sterility have been found in characters like seed production and longevity. No general correlation between sex phenotype and cyanide-resistant respiration capacity, or with any other respiration component, was found. Only in a single cross a strong correlation between cyanide-resistant respiration activity and sex phenotype was established, male steriles possessing the higher activity. The conclusion from these experiments is that there is no pleiotropic relationship between respiration levels and sex phenotype. The strongly significant correlation mentioned is ascribed to chromosomal linkage.     

Farnesylacetone, a sesquiterpenic hormone of Crustacea, inhibits electron transport in isolated rat liver mitochondria

Farnesylacetone (C18 H30 0) is a male hormone extracted from the androgenic gland of crab, Carcinus maenas. Appropriate enzymatic assays, as well as spectrophotometric studies, indicate that micromolar concentrations of farnesylacetone interact with the electron transport pathway of rat liver mitochondria. By the use of artificial electron donors and electron acceptors, it is shown that farnesylacetone immediately inhibits the electron transfer within complex I (NADH ubiquinone reductase activity) and complex II (succinate ubiquinone reductase activity). It is proposed that farneylacetone could interact with these two complexes of the respiratory chain at the level of the iron-sulfur centers implicated in the dehydrogenase activities. These observations are compared with the results obtained with terpenic molecules which interact with mitochondrial respiration.     

Distribution of neurons in the major pelvic ganglion of the rat which supply the bladder,colon or penis

Summary In male rats a large number of the postganglionic neurons which innervate the pelvic organs are located in the major pelvic ganglion. In the present study we have identified the location within this ganglion of neurons which project to either of three pelvic organs, the penis, colon or urinary bladder. Two fluorescent retrogradely-transported dyes, Fast Blue and Fluoro-Gold, were used. For most animals one dye was injected into the cavernous space of the penis, the wall of the distal colon or the wall of the urinary bladder. In a small number of animals two organs were injected, each with a different dye. One to six weeks after injection the major pelvic ganglia were fixed in buffered formaldehyde. The distribution of fluorescent dye-labelled cells was observed in whole mounts of complete ganglia and, in most cases, also in small accessory ganglia located between the ureter and the prostate. The studies showed a unique pattern of distribution for each organ-specific group of neurons. Most of the colon neurons are located in the major pelvic ganglion near the entrance of the pelvic nerve, whereas almost all of the penis neurons are near or within the penile nerve. Bladder neurons are relatively evenly distributed throughout the ganglion. These results demonstrate a distinct topographical organization of organ-specific neurons of the major pelvic ganglion of the male rat, a phenomenon which has also been observed in other peripheral ganglia.     

Allogrooming, partner choice, and dominance in male anubis baboons

This study was designed to test the hypothesis that among unrelated male baboons (Papio cynocephalus anubis) in single-gender social groups there is no significant association between dominance status and allogrooming performance. The hypothesis was tested using behavioral measures obtained by focal animal sampling techniques. The results indicate that unrelated male baboons established well-defined linear dominance hierarchies, formed allogrooming relationships with one another, and exhibited a nonrandom distribution of allogrooming; however, there were no significant relationships between dominance rank and the frequency of allogrooming. We further tested our results by grouping individuals into three dominance status classes (high, middle, and low) and comparing the classes. Analysis of variance demonstrated no significant differences in rates of allogrooming by dominance class. These results suggest that dominance did not account for the variation in observed allogrooming behavior: Dominance status did not appear to determine the frequency with which animals groomed others, the number of grooming partners, or frequency of grooming that any individual received in comparison to that performed. High-ranking animals did not have significantly more grooming partners than low-ranking animals, and there appeared to be little competition within the groups for subordinates to groom high-ranking animals. When age, kinship, and group tenure are controlled, performance and reception of allogrooming are not strongly associated with dominance in single-gender social groups of male anubis baboons.