Ancient DNA from Bronze Age bones of European rabbit (Oryctolagus cuniculus)

The European rabbit (Oryctolagus cuniculus) is now widely distributed throughout the world as a result of transportation by man. The original populations, however, were confined to southern France and Spain. In order to investigate the role of human intervention in determining the genetic diversity of rabbit populations, we are studying the origin of rabbits introduced onto a small Mediterranean island (Zembra) near Tunis over 1400 years ago, by examining ancient DNA extracted from rabbit bones found both on Zembra and on the European mainland. Ancient DNA was successfully extracted from rabbit bones found at two archaeological sites dated to at least the Early Bronze Age (more than 3500 years ago) in south-central France, and compared to that found in modern mainland and island populations using a small variable region of the cytochromeb gene. The results confirm that the Zembra Island population is descended from that present over 1400 years ago. The technical aspects of DNA extraction from bones and the implications of this type of research for determining the origin of introduced rabbit populations are discussed.     

Ultrastructure of 30–40 million year old leaflets from Dominican amber (Hymenaea protera,Fabaceae: Angiospermae)

Hymenaea protera leaflet fossils entombed in amber, dated at 30 to 40 million years (mine strata and exomethylene dating) were observed by both light and transmission electron microscopy. Ultrastructure preservation in these leaflets shows the presence of chloroplasts with thylakoid membranes, cell walls, mitochondria with associated endoplasmic reticulum, nuclei, and xylem tissue. Tissues show varying degrees of degradation; however, natural resin, which has perfused the cells, seems to maintain the structural integrity of the membranes and walls. We conclude that preservation of amber entombed organisms results from dehydration and slow fixative properties leaving the ultrastructure in excellent condition. These findings parallel reports on the exceptional preservation of amino acids and of DNA in amber-entombed organisms.     

An analysis of allozyme,mitochondrial DNA and morphological variation in mussel (Mytilus galloprovincialis) populations from Greece

Three populations ofM. galloprovincialis from northern Greece were investigated using isozyme analysis, discriminant analysis of morphological characteristics and analysis of restriction fragments of mtDNA. For all three types of analysis significant intra- and interpopulation differentiation was found. This differentiation is very noticeable at the mtDNA genotype frequencies. Furthermore, the restriction patterns of mtDNA were different from those reported for Atlantic populations of this species.     

Hymenaea protera sp.n. (Leguminosae,Caesalpinioideae) from Dominican amber has African affinities

Hymenaea protera is described from amber originating from La Toca mine in the Dominican Republic. The fossil species is characterized by the presence of reduced petals as well as distinctly clawed showy petals with cordate to reniform bases and a glabrous, verrucose ovary with long hirsute hairs at its base and along one margin. The fossil species most closely resembles the extantH. verrucosa Gaertner which occurs in East Africa and adjacent islands. These findings are interpreted as supporting a hypothesis that the genusHymenaea arose in the late Cretaceous on the combined South American-African continents and that Cretaceous and early Tertiary landmass movements were significant in determining the present amphi-Atlantic distribution of the genus. It is proposed that at least the majority, if not all, of the amber recovered from La Toca mine and other mines in the vicinity with similar-aged deposits originated fromH. protera.     

An improved test for Africanized honeybee mitochondrial DNA

Mitochondrial DNA derived fromApis mellifera scutellata, the ancestor of the Africanized bees of the New World, lacks aBglII restriction site found in other types of honeybee^1,2. We present primers allowing amplification of a 485-bp section of the cytochrome b gene containing this site, using the polymerase chain reaction. Digestion of the amplifiel product withBglII yields contrasting patterns between Africanized and other honeybees.     

Polymorphisms in mitochondrial DNA of european and Africanized honeybees (Apis mellifera)

Summary This study demonstrates polymorphisms in both the length and in the restriction enzyme cleavage sites of honeybee mitochondrial DNA (mtDNA). The levels of variation are typical of those found in other metazoan species. These polymorphisms are potentially useful for the identification of Africanized bees in the western hemisphere and for study of honeybee phylogenetics.     

DNA in wheat seeds from European archaeological sites

We have used hybridization analysis to detect ancient DNA in wheat seeds collected from three archaeological sites in Europe and the Middle East. One of these samples, carbonizedT. spelta dated to the first millennium BC, has yielded PCR products after amplification with primers directed at the leader regions of the HMW (high molecular weight) glutenin alleles. Sequences obtained from these products suggest that the DNA present in the Danebury seeds is chemically damaged, as expected for ancient DNA, and also indicate that it should be possible to study the genetic variability of archaeological wheat by ancient DNA analysis. Finally, we describe a PCR-based system that enables tetraploid and hexaploid wheats to be distinguished.     

Mitochondrial DNA variation in geographic populations of Colorado potato beetle,Leptinotarsa decemlineata (Coleoptera; Chrysomelidae)

Summary This study demonstrates variability in restriction enzyme cleavage sites of mitochondrial DNA (mtDNA) among four popalations of Colorado potato beetle (CPB). A suite of three enzymes (EcoRI,HpaI,PstI) was sufficient to discriminate among the populations tested. Individuals heteroplasmic for restriction enzyme patterns were found in some populations. Variability in CPB mtDNA should prove useful in efforts to trace the origin and dispersal of the species in North America.     

A mitochondrial DNA polymorphism in honeybees (Apis mellifera L.)

Summary Mitochondrial DNA (mtDNA), isolated from worker honeybee larvae, was digested by each of seven 6-base restriction enzymes. Only one enzyme (BglII) showed a mtDNA difference between the three tested races (Apis mellifera carcia, A. m. ligustica, A.m. caucasica). BothA.m. carnica andA.m. ligustica showed the same pattern, differing fromA.m. caucasica. The degree of fragment pattern similarity revealed that there is only a small level of mtDNA variation between the three races tested. This is in line with previous investigations of enzyme polymorphisms.     

Development of DNA probes for cytotoxin and enterotoxin genes in enteric bacteria

Summary DNA probes to identify the genes encoding toxins in enteric bacteria have been developed. Use of these probes reduces the number of animals required for toxicity testing, as suspect bacteria can be directly tested for the presence of toxin. We have augmented the gene probes available by developing probes against theEscherichia coli enterotoxin LTII and shiga toxin fromShigella dysenteriae 1.The LTII gene fromE. coli 357900 was identified and characterised and a suitable internal probe was obtained. The LTII gene was found not to be common among enterobacteriae from various geographical locations. Isolates predominately of animal origin from Nigeria and Thailand hybridized with the probe.The shiga toxin gene was isolated fromS. dysenteriae 1 by a combination of in vivo and in vitro methods. An internal probe was identified and used against different serogroups ofShigella andE. coli isolated. The probe was found to hybridize withS. dysenteriae 1 isolates and also someS. flexneri andS. sonnei strains. Representatives were tested for toxin production and found to produce toxin at low levels.     

Transfer of secondary metabolites from the spongesDysidea fragilis andPleraplysilla spinifera to the mantle dermal formations (MDFs) of the mudibranchHypserlodoris webbi

The opisthobranch molluscHypselodoris webbi is able to select, among its potential preys, sponges chemically rich in furanosesquiterpenoids. The sequestered secondary metabolites act as defensive allomones against predators and are accumulated in some dorsal glands (MDFs). This transfer from sponges to MDFs has been proven by maintainingH. webbi together with some selected sponges in an aquarium for a prolonged period.     

DNA synthesis in the nuclei of differentiating muscle fibers of the silkworm,Bombyx mori L.

Summary Incorporation of³H-thymidine (³HTdr) into the nuclei of myofibril-containing myofibers of larvae of the silkworm,Bombyx mori, was shown by means of light microscope (LM) and electron-microscope (EM) autoradiography. The number of DNA-synthesizing myonuclei attains 42% 12–18 h after each molt. Thus in the developing silkworm DNA replication and myofibrillogenesis are coexisting and not mutually exclusive processes as is the rule in vertebrate somatic myogenesis.     

Gel-electrophoretic description of European populations ofTerellia virens (Loew) (Diptera,Tephritidae); implications for its use as an agent for the biological control ofCentaurea spp. (Asteraceae) in North America

Allozyme frequencies of 15 enzyme loci, 14 of which were polymorphic, were used to characterize sevenTerellia virens populations originating from three allopatrically distributedCentaurea species. The two populations whose origins were geographically furthest apart, from Israel (onC. iberica) and from Switzerland (onC. vallesiaca), showed relatively high values of genetic distance from the 5 populations sampled in Austria and Hungary (onC. maculosa) (Nei's D>0.07). The latter five displayed a high degree of genetic similarity. No diagnostic (fixed) allelic differences were observed between these three groups ofT. virens populations, but they could be well characterized by significant differences in allelic frequencies at 9 enzyme loci. Independently of this study, the populations from Switzerland (C. vallesiaca) and eastern Austria (C. maculosa) were selected as potential source populations for future introductions into North America for the biological control of introducedC. maculosa andC. diffusa. Based on the observed genetic differences and results from field experiments on the host specificity of these two potential source populations, it is argued that host specificity screening tests should be conducted separately for local (host plant) populations, as such populations might accept a different set of hosts. Biotype mismatch and the risk of spill-overs to native species could thus possibly be reduced.     

4,11-Epoxy-cis-eudesmane,soldier cephalic secretion of the Nearctic desert termite,Amitermes minimus Light (Termitidae: Termitinae)

Summary The soldier cephalic secretion of the Nearctic desert termite,Amitermes minimus, consists almost entirely of 4,11-epoxy-cis-eudesmane which was previously identified from soldiers of 2 AfricanAmitermes species. Soldiers ofA. minimus each store circa 61 g of the secretion. Bioassays with the ant,Crematogaster californica, indicate a repellent role for the eudesmane compound in termite defense.Classification as proposed by Sands, W.A., Bull. Br. Mus. nat. Hist., Ent., suppl.18 (1972).Supported by Sigma Xi Grant-in-Aid of Research and California Statewide Critical Applied Research grant.     

Albumin concentration in plasma of two related species ofCeratophrys (Anura Leptodactylidae) from two different environments

Summary Albumin concentration in plasma of two related species ofCeratophrys, C. cranwelli andC. ornata was analyzed and shown to be higher in the former species, which is the adaptive form found in dry areas.     

Multiple roles of the DSCR1 (Adapt78 or RCAN1) gene and its protein product Calcipressin 1 (or RCAN1) in disease

The DSCR1 (Adapt78) gene¹ is transiently induced by stresses to temporarily protect cells against further potentially lethal challenges. However, chronic expression of the DSCR1 (Adapt78) gene has now been implicated in several pathological conditions including Alzheimer’s disease, Down syndrome and cardiac hypertrophy. Calcipressin 1 has been shown to function through direct binding and inhibition of the serine threonine protein phosphatase Calcineurin. Pharmacological inhibition of calcineurin, by the immunosuppressive drugs cyclosporin A and FK506, affects a wide variety of diseases. It is, therefore, likely that this endogenous calcineurin inhibitor, calcipressin 1, may also play a role in a variety of human diseases. ¹Please note that the mammalian DSCR1 gene is also called Adapt78 or RCAN1, and its protein products have been named Calcipressin1, MCIP1 and RCAN1. A proposal to adopt a single gene name of RCAN1 and a protein name RCAN1 (for Regulator of Calcineurin) has been endorsed by the HUGO Gene Nomenclature Committee, but final approval must await agreement from a majority of researchers in the field. Received 2 March 2005; received after revision 27 May 2005; accepted 19 July 2005