Ten polymorphic microsatellite loci for the endangered Buena Vista Lake shrew (Sorex ornatus relictus)

The ornate shrew (Sorex ornatus) is restricted to the vanishing wetlands of California, USA and Baja California, Mexico. Several subspecies of ornate shrews are considered ‘mammal species of special concern’ in California by the Department of Fish and Game, and one (Sorex ornatus relictus) has recently been listed as endangered. Populations of shrews around Buena Vista Lake have been diminished or extirpated due to habitat deterioration and human development. In order to study the patterns of genetic variation in isolated populations of Buena Vista Lake shrews, we developed 10 polymorphic microsatellite loci. There were 6–27 alleles per locus, and the loci had heterozygosity values that ranged from 20 to 80%. In addition, we screened 20 different populations of S. ornatus, eight species within two subfamilies of shrews (Soricinae and Crocidurinae), as well as in a mole (Talpidae, Neurotrichus gibbsii), to determine if these loci could be informative in other species as well.     

A genetic comparison of two species of clam shrimp in the genus Eulimnadia: An electrophoretic approach

Herein we report the first genetic comparison among species in the genus Eulimnadia. Multilocus genotypic patterns (using six allozyme loci) were compared for a total of 2277 clam shrimp from nine populations from Arizona and New Mexico. Seven of these populations were morphologically typed as Eulimnadia texana Packard and two were typed as Eulimnadia diversa Mattox. All populations were hermaphrodite-biased, and highly inbred (inbreeding coefficients ranging from 0.33 to 0.98). Genetic distances showed the two species to be within the range described for other arthropods. One of the two E. diversa populations appeared to be a hybrid between E. texana and E. diversa, showing electrophoretic patterns similar to both species, although morphologically, they were typed as E. diversa. A phenogram (generated using coancestry distances and a neighbor joining algorithm) placed this hybrid population half-way between these two species, and a breakdown of individuals within this hybrid population (based on allozyme scores) indicated individuals very similar to the second E. diversa population, and two groups of apparent hybrid individuals. Therefore, the distinction between these two species is questionable due to their apparent hybridization in this area of Arizona. Genetic population structuring was noted among the seven E. texana pools. Estimated migration rates were less than one migrant per generation. Even in the geographically close pools in New Mexico, which were separated by only hundreds of meters, significant sub-structuring was noted, and estimates of migration rate were less than two migrants per generation.     

Isolation and characterization of 30 polymorphic microsatellite loci from the mycophagous fly Drosophila innubila

Drosophila innubila is a mushroom-feeding member of the quinaria group, found in the woodlands and forests of the 'sky islands' in Arizona and New Mexico and extending south into central Mexico. Here, we describe and characterize 30 polymorphic microsatellite loci from D. innubila collected in the Chiricahua Mountains in Arizona. The number of alleles ranged from three to 21, and observed heterozygosity ranged from 0.0513 to 0.9737. Six loci were putatively X-linked, six departed from Hardy-Weinberg equilibrium, seven had evidence of null alleles, and six showed evidence of linkage disequilibrium. These markers will be useful for examining population structure of D. innubila and its association with male-killing Wolbachia.     

Characterization of microsatellite loci in Kearney's bluestar (Amsonia kearneyana) and cross‐amplification in other Amsonia species

Kearney's bluestar (Amsonia kearneyana) is a highly endangered herbaceous perennial in the family Apocynaceae. The species is found only in the Baboquivari Mountains of southern Arizona. We report the isolation and development of 12 microsatellite loci for Kearney's bluestar. Numbers of alleles ranged from two to four and observed heterozygosities ranged from 0.20 to 0.80 in the nine loci found to be polymorphic in the test population. All loci were also tested for cross‐amplification in five other Amsonia species representing two subgenera from the southwestern United States. Some loci that were not polymorphic in the Kearney's bluestar were polymorphic in other species.     

Another look at Hymenoxys subgenus Plummera (Asteraceae: Heliantheae: Gaillardiinae) from Arizona and New Mexico

The recent merger ofPlummera intoHymenoxys is followed here. The two previously recognized species ofPlummera are here treated as a single polymorphic species ofHymenoxys, H. ambigens, consisting of three varieties: var.ambigens from the Mescal, Santa Teresa, and Pinaleno Mountains of southeastern Arizona; var.floribunda from the Chiricahua, Dos Cabezas, Dragoon, Little Dragoon, and Mule Mountains of southeastern Arizona; and var.neomexicana described here from the Animas and Peloncillo Mountains of southwestern New Mexico.     

Characterization of microsatellite markers for the mangrove tree Avicennia germinans L. (Avicenniaceae)

We describe 10 primers for amplification of microsatellite loci for the mangrove, Avicennia germinans. Eight loci were isolated from a DNA sample from the Pacific coast of Baja California, Mexico and two loci were isolated from a DNA sample from the Atlantic coast of Bermuda. Polymorphism was investigated in a population from the Mexican Pacific coast (n = 15) and in four samples scattered throughout the range of the species. Total number of alleles for the species ranged from two to 10. Observed heterozygosity in the Mexican Pacific coast population ranged from 0.27 to 0.60, with two loci having fixed alleles.     

Isolation of polymorphic microsatellite loci in the ponerine ant Ectatomma tuberculatum

We report the development of 11 microsatellite markers by an enrichment protocol in the ponerine ant Ectatomma tuberculatum. Polymorphism was explored in two colonies collected from Mexico and two colonies from Brazil. From the 11 loci which amplified, seven loci showed intracolonial polymorphism in Mexican colonies and only six loci were variable in populations from Brazil. Observed heterozygosity ranged from 0.18 to 0.84. The other five loci exhibited different alleles between Mexico and Brazil but geographical variability was not investigated further. Cross‐amplification was tested in another species of the same Tribe (Gnamptogenys striatula) and one locus was revealed to be polymorphic.     

Variation in DNA microsatellites of the ferruginous pygmy-owl (Glaucidium brasilianum)

Eleven polymorphic microsatellite loci were used to assess genetic variation in the ferruginous pygmy owl (Glaucidium brasilianum) from North America. Analysis of genotypic variation suggests restricted gene flow between pygmy-owl populations in Arizona-Sonora and Sinaloa, and Texas and the remaining states in Mexico. The Arizona-Sonora population showed signs of a recent genetic bottleneck, an observation supported by low population estimates for Arizona (13–117 individuals). Heterozygosity in Arizona, however, was equal to levels recorded throughout Mexico and Texas. Congruent patterns revealed by nuclear (microsatellites) and mitochondrial DNA that indicate Arizona-Sonora and Texas populations are distinct from adjacent populations in Mexico, thus emphasizing need for the design and implementation of separate management plans for recovery and conservation efforts. Revealing evidence of distinct groups within the pygmy-owl populations in North America, results from this study may be used to make management decisions for the recovery and conservation of this species.     

PATTERNS OF FLORAL NECTAR-SUGAR COMPOSITION OF IPOMOPSIS LONGIFLORA (POLEMONIACEAE) NEAR THE CONTACT ZONE OF ITS SUBSPECIES LONGIFLORA AND AUSTRALIS

The nectar-sugar compositions of 338 individuals from 27 populations in two subspecies of Ipomopsis longiflora from Arizona, New Mexico, Texas, and Chihuahua were determined by high-performance liquid chromatography. Mean sucrose compositions of populations ranged from 73.2% to 91.9%, and the standard deviations ranged from 1.9% to 9.1%. Pairs and aggregates of populations were statistically compared. The nectar-sugar compositions of the two subspecies were significantly different as aggregates. Subspecies australis averaged 9.5% fructose, 7.9% glucose, and 82.6% sucrose while subspecies longiflora averaged 7.8% fructose, 5.7% glucose, and 86.5% sucrose. Each subspecies was found to have two groups of populations. Groups of higher sucrose populations were found along the contact zone of the subspecies; away from the contact zone both subspecies had groups of lower sucrose populations. The data show that significant variability exists in this biochemical character, and the pattern of variation is clearly related to the geographic distribution of the populations. The genetic and selective mechanisms involved are unknown.     

HOW DISCRETE ARE OAK SPECIES? INSIGHTS FROM A HYBRID ZONE BETWEEN QUERCUS GRISEA AND QUERCUS GAMBELII

The white oaks Quercus gambelii and Q. grisea overlap in distribution in New Mexico and Arizona. Within the region of overlap, there are numerous instances of contact between the two taxa. In some areas of contact morphologically, intermediate trees are common, whereas in others, morphologically intermediate trees are rare or absent. We describe a set of RAPD markers that distinguish between the two species and use these markers to examine patterns of gene exchange in an area of contact in the San Mateo Mountains of New Mexico. The markers are highly coincident with morphology and confirm that hybridization between the two species takes place. Despite the occurrence of hybrids, both species remain distinct, even in areas of sympatry, and marker exchange appears to be limited.     

STUDIES IN THE QUERCUS UNDULATA COMPLEX. IV. THE CONTRIBUTION OF QUERCUS HAVARDII

Scrub oak populations in the semidesert area of northeastern Arizona and southeastern Utah are ordinarily identified in regional manuals as Quercus undulata. They are very similar, both morphologically and ecologically, to Q. havardii of the Staked Plain of the Texas Panhandle and southeastern New Mexico. They differ, however, in a number of inconspicuous characters. Population sample analyses indicate that most of these differences are suggestive of Q. gambelii, and the deviant populations are thus interpreted as having been derived from ancestral Q. havardii through introgression by Q. gambelii. Two differences are not in accord with this interpretation; these are regarded as possible cases of transgressive segregation. Considering the evolution of these hybridized populations, it is speculated that the ancestral Q. havardii occurred to the south and west of the present range of this species during the Kansan period of the Pleistocene. During subsequent northward dispersal, it became split in two. The eastern portion ultimately came to occupy the present range of the species in the Staked Plain; the western portion—lying to the west of a north-south mountain barrier in central New Mexico—became introgressed by Q. gambelii (and locally by Q. turbinella), resulting in the present populations of Arizona and Utah.     

Taxonomy of <Emphasis Type="Italic">Koeberlinia</Emphasis> (Koeberliniaceae)

Koeberlinia has a natural amphitropical distribution that includes the deserts of central Bolivia, northern Mexico, and the southwestern United States. Despite the long recognition of only one species, K. spinosa, field, herbarium, and SEM studies support the recognition of two species. Koeberlinia spinosa of northern Mexico and adjacent United States is recognized to consist of three varieties: K. spinosa var. spinosa of northeastern Mexico and the adjacent United States, K. spinosa var. tenuispina of the Sonoran Desert of southwestern Arizona, adjacent California, and northwestern Mexico, and K. spinosa var. wivaggii from south central Texas and northern Mexico to Arizona, which is described as new. Koeberlina holacantha, endemic to the deserts of Bolivia, is proposed as new.     

Trichinella infection in wildlife of the southwestern United States.

Several potential mammalian reservoirs of sylvatic species of Trichinella were examined from Texas, New Mexico, and Arizona. During 1998-99, tongues were collected from a black bear (Ursus americanus) in Arizona; from 9 black bears, a coyote (Canis latrans), and a mountain lion (Felis concolor) in New Mexico; and from 154 coyotes, 32 raccoons (Procyon lotor), 13 opossums (Didelphis marsupialis), 4 ocelots (Leopardus pardalis), 3 bobcats (Lynx rufus), and 5 feral hogs (Sus scrofa) in southern Texas. Larvae of Trichinella murrelli were identified by a multiple-polymerase chain reaction analysis in 1 black bear (11.1%) from New Mexico and in 7 coyotes (4.5%) of Texas, whereas Trichinella spiralis larvae were detected in the black bear of Arizona. This is the first report of Trichinella infection in wildlife of New Mexico and Texas and extends the distribution of T. murrelli into the southwestern United States near the border of Mexico.     

Isolation and characterization of microsatellites in the columnar cactus: Polaskia chichipe and cross‐species amplification within the Tribe Pachycereeae (Cactaceae)

Microsatellite markers were developed for the columnar cactus Polaskia chichipe from central Mexico. After an enrichment procedure and three screening steps 87% of colonies contained microsatellites. A pair of primers for 10 loci (seven polymorphic) were developed, tested and used to estimate variation in samples of 18–45 individuals from the Tehuacan Valley, Mexico. Alleles per locus ranged from two to eight (mean 5.28; SD 2.5). Range of expected heterozygosity values was 0.188–0.797 (mean 0.502; SD 0.25). These loci are particularly useful for more precise evolutionary studies, such as gene flow and breeding systems, for this cactus species.     

Reproductive success and genetic divergence among varieties of the rare and endangered <Emphasis Type="Italic">Astragalus cremnophylax</Emphasis> (Fabaceae) from Arizona,USA

Populations of Astragalus cremnophylax from Arizona and related A. humillimus from New Mexico were assessed for morphological, reproductive, genetic, and ecological differences. Results suggest that some of the taxa (i.e., A. cremnophylax var. cremnophylax and A. humillimus) are poor reproducers and environmental fluctuation is not likely a factor contributing to low fecundity in these species. Astragalus cremnophylax var. cremnophylax appears to have low fecundity due to inbreeding depression. Allozyme data from 18 loci show little within-population and taxon genetic variability. Most genetic variability is distributed among populations and taxa. The population of A. cremnophylax var. cremnophylax from the Grand Canyon (South Rim) was genetically depauperate, indicative of the bottleneck caused by historic trampling at this viewpoint. Cape Final, a population of A. cremnophylax var. cremnophylax on the Grand Canyon (North Rim) is genetically different from typical materials of this taxon (South Rim) and is more closely related to other taxa within this species complex. However, the other varieties of A. cremnophylax are more closely related to A. humillimus than the population at Cape Final, suggesting potential species status for Cape Final materials based on allozyme divergence.     

Eight polymorphic microsatellite markers for kelp bass,Paralabax clathratus,amplified in three multiplex polymerase chain reaction sets

Kelp bass, Paralabrax clathratus, is an important sport fishery of California, USA and Baja, Mexico. Here we describe eight microsatellite loci developed for this species. Two loci were derived from known primers for other species in the family, Serranidae and six were developed anew using a clone enrichment protocol. Loci were arranged into three multiplex PCR (polymerase chain reaction) sets for fast throughput; 564 individuals from nine populations across the species’ range were genotyped. Polymorphism ranged from four to 47 alleles and all populations at all loci displayed Hardy–Weinberg and linkage equilibrium.     

Multivariate discrimination among cryptic species of the mite genus Chaetodactylus (Acari: Chaetodactylidae) associated with bees of the genus Lithurgus (Hymenoptera: Megachilidae) in North America

Twenty-seven morphological characters from 111 heteromorphic deutonymphs of the mite genus Chaetodactylus Rondani (Acari: Chaetodactylidae) were analyzed. The mites were collected from four species of bees of the genus Lithurgus Berthold (Hymenoptera: Megachilidae) in continental North America. Principal component and canonical variates analyses on Darroch and Mosimann shape and size-and-shape variables revealed the presence of three cryptic species. Chaetodactylus gibbosi sp. n. (Florida) is geographically isolated from C. lithurgi sp. n. distributed in Texas, New Mexico, Arizona, Colorado, and Idaho. Sympatric C. lithurgi and C. abditus sp. n. (USA: Arizona, Mexico: Socorro Is.) are seasonally isolated in Arizona. Chaetodactylus gibbosi is associated with a single bee species, Lithurgus gibbosus Smith in Florida. The host range of C. lithurgi includes bees flying predominantly in the spring: L. apicalis Cresson, L. littoralis Cockerell, and western L. gibbosus. Chaetodactylus abditus sp. n. is associated with L. planifrons Friese and L. echinocacti Cockerell, flying predominantly in the fall in Arizona. No distinct groups separated by geographic locality or size were detected in any species. A six-variable model developed by the canonical variates analysis and estimated using jackknife resampling and external validation (n=100) is capable of classifying the three species with 100% accuracy. Factors that influenced speciation of cryptic species of Chaetodactylus associated with Lithurgus are discussed. Based on morphological and geographical data and data on mite associates, the western and eastern populations of the bee L. gibbosus are distinct. Therefore, the taxonomic status of L. gibbosus s. lat. should be reevaluated.     

Microsatellite Loci of the Cattle Tick Boophilus Microplus (Acari: Ixodidae)

This brief communication reports the identification of microsatellite loci in the economically important tick species Boophilus microplus. The data are potentially useful in distinguishing different strains of B. microplus. Eight polymorphic loci were isolated in larvae, male and female adults analysed individually from 12 field isolates and laboratory strains from Australia (n = 8), Brazil, Mexico, Papua New Guinea and Zimbabwe. Nucleotide sequencing of alleles at these microsatellite loci revealed that non-repeat bases interrupted dinucleotide and tetranucleotide repeats in some loci. Loci with non-repeat bases interrupting them were shorter compared with loci that were not interrupted. Thus the presence of non-repeat bases in a repeated sequence seems to constrain the evolution of additional repeats by slip-strand misparing at these loci.     

LYSSOXYLON GRIGSBYI,A CYCAD TRUNK FROM THE UPPER TRIASSIC OF ARIZONA AND NEW MEXICO

Lyssoxylon grigsbyi Daugherty, a petrified stem with petiole bases, was originally described from the Upper Triassic Chinle Formation of Arizona and considered to be a member of the Williamsoniaceae. Investigation of additional material from a similar horizon in New Mexico, together with re-examination of preparations of the holotype, suggest that the plant, with its monoxylic stele, girdling leaf traces, and bicelled epidermal hairs is a true cycad. Cells of the New Mexico specimens contain structures interpreted as preserved nuclei.