DNA Sequences from Formalin-Fixed Nematodes: Integrating Molecular and Morphological Approaches to Taxonomy

To effectively integrate DNA sequence analysis and classical nematode taxonomy, we must be able to obtain DNA sequences from formalin-fixed specimens. Microdissected sections of nematodes were removed from specimens fixed in formalin, using standard protocols and without destroying morphological features. The fixed sections provided sufficient template for multiple polymerase chain reaction-based DNA sequence analyses.     

Ideas in theoretical biology

The potential and realized impact of Bohm's views on biology are briefly discussed.     

Skeletal biology of the Taino: a preliminary report

Preliminary data on the skeletal biology of 78 Taino skeletons belonging to Juan Dolio, an archaeological site of the Maguana province, 80 Km. east of S. Domingo, are presented. The minimum number of individuals, sex, age, stature, and morphologic and morphometric characters were determined. Dental wear and pathology of cranial and post-cranial bones were also recorded.     

Neuropeptide gene expression and neural activity: Assessing a working hypothesis in nucleus caudalis and dorsal horn neurons expressing preproenkephalin and preprodynorphin

1. The working hypothesis that neuropeptide gene expression in a neuron is an indicator of that neuron's physiological activity is discussed. 2. Representative examples from the literature are presented to support the hypothesis. 3. Further, we discuss the regulation of expression of two opioid peptides, preproenkephalin and preprodynorphin, in laminae I and II of the spinal cord and in nucleus caudalis of the trigeminal nuclear complex, where they may play a role in pain modulation. 4. The expression of the opioid peptide genes can be induced by both painful and nonnoxious stimuli in neurons in time-dependent and sensory-specific fashions.     

Postcranial variations in late Epigravettian and Neolithic human remains from Arene Candide cave (Liguria,Italy)

Late Epigravettian postcranial human remains from the Arene Candide cave (Finale Ligure, Savona, Italy) were compared with the Neolithic sample found in the upper levels of the same site. Data on length, diaphyseal circumference and diameter of clavicle, humerus, radius, femur and tibia were collected from male specimens having all these bones. The Epigravettian sample is characterized by significantly greater tibial length, robustness and platycnemia, significantly lower circumferences in the upper limb bones and the clavicle, and a high degree of asymmetry. Variations observed in lower limb bones are those expected on the basis of the different functional requirements of a hunting and gathering economy compared to a more sedentary, food producing economy. Differences in the upper limb bones and the clavicle are less explicable. However, considering that in spite of a more slender structure, the Epigravettian bones show evidence of vigorous use, variation in upper limb could result from qualitatively different involvements.     

Reproductive lability in pre-dispersal biology ofRhamnus alaternus L. (Rhamnaceae)

Summary Rhamnus alaternus L. is a dioecious, fleshy-fruited shrub, typical of Mediterranean vegetation, which has been recorded from the region since the tropical Tertiary. Reproductive biology of this species has been studied in Southern Italy over a period of 4 years with both field and laboratory experiments. In all the studied populations male plants predominate over the females, have a higher flower density and flower regularly every year while females are usually alternate-bearing. A strong negative association between fruit formation and vegetative growth has been found indicating that the presence of fruits on a branch reduces the growth of new shoots. This phenomenon, together with alternate-bearing, is evidence of a strong competition between vegetative growth and reproductive activity and indicates resource limitation. Flower morphology and quantity of pollen produced are typical of insect pollinated species, and flies of the Empididae and Muscidae were trapped bearing pollen at female plants but pollen is also dispersed by wind. Field experiments on pollination success showed that the exclusion of insects as pollen vectors produces a significant decrease in fruit development. Excess pollen provided by hand-pollination increases fruit set over open-pollination and reproductive success in the field is therefore pollen limited. The variability of sex expression, male fitness, fruit production, regrowth and pollination presented here suggests that these predispersal characteristics ofR. alaternus have been subject to evolutionary change since the tropical Tertiary climate was replaced by a Mediterranean one. This points to the possibility that reproductive, as well as morphological and physiological characteristics, may be equally selected for in extreme environments such as the Mediterranean.     

Redescription ofDiaphanosoma volzi Stingelin, 1905 (Crustacea: Daphniiformes: Sididae) with remarks on comparative morphology,biology and geographical distribution

The rareDiaphanosoma volzi Stingelin, long confused withD. sarsi Richard andD. celebensis Stingelin, is redescribed, based on extensive material of parthenogenetic and gamogenetic females and males from Thailand. Indonesia, Malaysia, Philippines, India, Australia and Sudan, and a study of intra- and interpopulation morphological variability. Compared with otherDiaphanosoma species, it shows the greatest degree of oligomerization and specialization. It is widely distributed in the tropics and subtropics of the Eastern hemisphere, and mostly occurs in shallow, vegetated habitats.