Starch Gel Electrophoresis Research Articles

Characterization of a novelEntamoeba histolyticastrain from Burkina Faso, Africa, possessing a unique hexokinase-2 gene

An Entamoeba histolytica strain (BF-841 cl1) that originated from Burkina Faso, Africa presented with novel, polymorphic genotypes of the serine-rich E. histolytica protein and the anodic hexokinase-2 (HXK-2) isoenzyme band, which showed less electrophoretic mobility than that of an E. histolytica reference strain [HM-1:IMSS cl6 (zymodeme (Z)-II)] by starch gel electrophoresis and isoelectric focusing (IEF). The HXK-2 gene of BF-841 cl1 had amino acid variations at four positions compared to the sequence of HM-1: IMSS cl6. These variations were absent from the sequences of four other E. histolytica strains with different zymodemes [KU27 (Z-II), SAW1627 (Z-IIα-), SAW755CR clB (Z-XIV), and KU2 (Z-XIX)]. The results of IEF showed no difference in the substrate specificity of HXK (HXK-1 and HXK-2) between BF-841 cl1 and the three reference E. histolytica strains (HM-1:IMSS cl6, SAW755 clB, and KU27). It was also confirmed that BF-841 cl1 was able to form liver abscesses in Syrian hamsters.

Polymorphism of hordein-coding loci in barley (Hordeum vulgare L.) populations of Iran and Central Asian countries

Starch gel electrophoresis was performed to study polymorphism of hordeins encoded by the Hrd A, Hrd B, and Hrd Floci in 366 local old barley accessions from Iran and Central Asian countries, including Turkmenistan, Uzbekistan, Tajikistan (Mountain Badahsan), and Kirgizia. In total, 60 alleles with frequencies of 0.0003-0.2818 were observed for the Hrd A locus, 106 alleles with frequencies of 0.0003-0.1603 were observed for the Hrd B locus, and five alleles with frequencies of 0.0164-0.4131 were observed for the Hrd Flocus. The alleles and allele frequencies displayed irregular distributions in barley populations of the above countries. Cluster analysis of the matrix of allele frequencies in populations from known collection sites revealed a cluster structure of local barley populations within each country. Local populations formed five differently sized clusters in Iran, six in Turkmenistan, three in Uzbekistan, and three in Kirgizia. The variation and allele frequency distribution of the hordein-coding loci in Iran and Central Asian countries were assumed to result from the introduction and spreading of barley forms via migrations of husbandmen.

Haptoglobin polymorphism is not associated with prostate cancer in blacks

BackgroundProstate cancer (Pca) disease burden is highest among male blacks. Oxidative stress due to hemoglobin-related oxygen reactive species is a risk factor for cancer development. The polymorphic haptoglobin (Hp) protein inhibits hemoglobin-related oxidative stress. The antioxidant capacity of Hp is genetically determined. We studied the effect of Hp polymorphism on susceptibility to Pca. Subjects and methodsIn a case–control study, 201 participants (60 hospital-based controls, 62 benign prostate hypertrophy (BPH) and 79 prostate cancer (Pca) patients were studied. Serum prostate specific antigen (PSA) was measured using an immunoradiometric assay and Hp phenotype was determined using starch gel electrophoresis. Haptoglobin phenotype distribution was compared between groups according to disease state. ResultsSerum PSA concentrations were markedly elevated in BPH and Pca patients compared to control subjects. Overall, Hp 1–1 was present in 50 individuals (25%), Hp 2–1 in 91 persons (46%) and 46 subjects (23%) had Hp 2–2. Thirteen individuals (6%) were anhaptoglobinaemic. The Hp1 allele frequency was not significantly different according to clinical history; 0.472 (95% CI 0.343–0.601), 0.567 (95% CI 0.395–0.619) and 0.507 (95% CI 0.441–0.693) for control group, BPH and Pca patients, respectively. ConclusionOur results suggest that Hp polymorphism is neither associated with risk of developing Pca nor outcome of the disease.

Genetic diversity, population structure and relationships of Tunisian Thymus algeriensis Boiss. et Reut. and Thymus capitatus Hoffm. et Link. assessed by isozymes

The genetic diversity and population structure of two Tunisian Thymus species (Thymus algeriensis and Thymus capitatus), from 46 natural populations growing in six bioclimates, were analysed by starch gel electrophoresis using eight isozymes. The genetic diversity within populations varied at species level. Variation in T. algeriensis was higher than that observed for T. capitatus, and exclusive alleles were detected for the two studied species. A high differentiation among populations, for each species, estimated by Wright's F-statistics was revealed. In each species, a high level of inbreeding within populations induced by Wahlund effect was observed. A relatively high level of differentiation associated with a restricted gene flow among species was revealed. The PCA and UPGMA analysis, performed on all populations, showed two distinct groups with respect of specific differentiation level. The high genetic divergence between the two species corroborates their taxonomic status, as previously reported using morphological traits. The strategy for the management and conservation of populations should be made for each taxa according to its level of diversity and bioclimate.

Genetic divergence in the snorkel snail, Rhiostoma housei, a species complex in Thailand (Caenogastropoda: Cyclophoridae)

Abstract Allozyme variation was examined in 292 samples of the snorkel snail, Rhiostoma housei, collected from 12 localities within four regions of Thailand. Ten allozyme loci were screened across all the samples using horizontal starch gel electrophoresis, and eight of these loci, from eight enzyme systems, were found to be polymorphic. Within these eight loci the expected heterozygosity (Hexp) was moderate to high ranging from 0.015 to 0.148 with an overall mean of 0.081 ± 0.041, whilst a high genetic heterogeneity among samples was found (Fst = 0.798). R. housei exhibited a weak pattern of isolation by distance over the entire tested species range in Thailand. The high Fst and moderate to high Hexp suggest gene flow amongst populations is partially restricted resulting in fragmentation into local gene pools. Based on allele frequencies and an allozyme dendrogram, six groups were identified, and these entities may represent separate biological species. The large values of genetic distances and fixed allelic differences obtained for each combination of allopatric samples imply the presence of cryptic species under the name R. housei.

Genetic structure of the common terrestrial pulmonate snail, Cryptozona siamensis (Pfeiffer, 1856), in Thailand

Abstract Allozyme variation was examined in 432 specimens of the pulmonate snail, Cryptozona siamensis, from 24 localities across three regions of Thailand plus an additional population from Malaysia. Although this snail is a cosmopolitan species it was predicted that C. siamensis should exhibit a large degree of genetic subdivision across these regions due to a low level of inter-population gene flow. To test this hypothesis, 10 enzyme systems were screened using horizontal starch gel electrophoresis, from which 14 presumed allozyme loci were scored and 13 found to be polymorphic. For these 13 polymorphic loci the expected heterozygosity levels were moderate (Hexp = 0.036–0.183, mean = 0.101). Genetic differentiation among the samples was low, with a low FST value (0.254) and genetic distance (D = 0.000–0.124, mean = 0.034) and no significant isolation by distance (IBD) across the whole sampled range of Thailand or Thailand plus Malaysia. However, an IBD pattern in the population substructure in the central Thailand region was detected. The low FST and moderate Hexp values in various populations of C. siamensis suggests a high degree of gene flow/migration between populations across the three geographic regions of Thailand (northern, central and southern) as well as the sampled population in Malaysia, perhaps associated with the anthropochoric effect of snail dispersal. The apparent IBD in the central Thailand region could be the consequence of local dynamics though this region.

Association of haptoglobin phenotypes with the development of Kaposi’s sarcoma in HIV patients

Kaposi's sarcoma (KS) is a rare cutaneous tumor caused by human herpes virus-8 (HHV-8) infection that preferentially develops in case of severe immunosuppression, such as in HIV/AIDS disease. Haptoglobin (Hp), a polymorphic multifunctional plasma protein, exerts several immunomodulatory effects and is characterized by a genetic polymorphism leading to three major phenotypes (Hp 1-1, Hp 2-1 and Hp 2-2). This study investigated the influence of Hp genetic polymorphism on the development of KS in HIV-positive patients. 661 HIV patients were enrolled in the study with a median age of 35years and a median follow-up time of 57months. Hp phenotyping was performed using hemoglobin-supplemented starch gel electrophoresis. In case of low Hp concentration high pressure gel permeation chromatography (HPGPC) was used. The Hp 1-1 phenotype was associated with a significant higher risk of KS compared to the combined group of Hp 2-1 and Hp 2-2 patients (p<0.0005) which remained significant after adjustment for possible confounding variables (age, gender and AIDS status) (p<0.001). In contrast, the Hp 2-1 phenotype carried the lowest risk. These findings point to the involvement of Hp phenotypes in the pathogenesis of KS, which may be due to a difference in skin immunosurveillance between the Hp phenotypes.

The haptoglobin phenotype influences the risk of cutaneous squamous cell carcinoma in kidney transplant patients

Cutaneous squamous cell carcinoma (SCC) is the most frequent skin cancer after organ transplantation. Currently, the pre-identification of transplant patients at increased risk for non-melanoma skin cancer remains difficult. To investigate the Hp polymorphism as a marker for the identification of a subset of patients with an increased susceptibility to develop SCC/Bowen's disease. Haptoglobin phenotyping was performed with haemoglobin-supplemented starch gel electrophoresis in 300 kidney transplant patients. High-performance gel permeation chromatography was used in case of low serum haptoglobin concentration. Cox regression analysis (adjusted for age, gender and Mediterranean origin) showed a significant association of the Hp 1-1 phenotype with a higher risk of SCC/Bowen's disease (P = 0.035) and multiple primary SCCs (P = 0.002). No significant difference between the Hp phenotypes was found for the development of Bowen's disease and SCCs in the first 10 years following renal transplantation. However, after a follow-up of >10 years, a significant association between the Hp 1-1 phenotype and the occurrence of Bowen's disease and SCC was reported (P = 0.002 and P = 0.001 respectively). This study shows an increased risk for the development of (multiple) SCCs in kidney transplant patients with the Hp 1-1 phenotype. This finding points to the role of Hp 1-1 phenotype as an important predictor in identifying a subset of patients with an increased need for preventive measures and is in agreement with the decreased anti-inflammatory capacity of this phenotype.

Oliver Smithies: Born Inventor

> This profile of Oliver Smithies highlights many of the qualities of a great scientist: a down-to-earth, unassuming style (remember “the smaller the mind, the greater the conceit” as I wrote last year in my preamble to Eric Olson's profile); simplicity; an enduring passion for discovery and invention; and total commitment to the work. > > Smithies' statement that there is no substitute for hard work is one of the absolute truisms of life, as I elaborated last year in my preamble to Robert Lefkowitz's profile. No matter how smart you are, if you don't work hard, you will never make it. He is a living testimony of this concept. All of us should be astounded and inspired by the fact that this 85-year-old scientist, a Nobel laureate who has contributed so much to human knowledge, still works in the lab every day of the week, runs experiments, and exudes the same passion for science that he exuded 60 years ago. What a marvelous role model for young scientists. > > Smithies has used wisely the talent that he was given. Isn't that one of the most important things that we should be able to say about ourselves? > > Roberto Bolli In the 1980s, the work of Oliver Smithies, together with that of Mario Capecchi and Martin Evans, led to a whole new approach to studying mammalian genetics. These three scientists developed the necessary gene-targeting techniques that gave rise to knock-out mice.1,–,5 They were awarded the Nobel Prize for their work in 2007. Gene-targeting is a technique used by many modern molecular biologists. But a technique used by practically every molecular biologist, often several times a day, is running gels. Again, a large part of the thanks for developing this technique goes to Smithies who, in the 1950s, invented starch gel electrophoresis as …

Donor haptoglobin phenotype determines outcome following liver transplantation

Haptoglobin (Hp) is a polymorphic plasma protein with multiple functions defined by three major phenotypes (Hp 1-1, Hp 2-1, and Hp 2-2). In this article, the effects of the donor Hp phenotype (determined by starch gel electrophoresis) on the outcome and the iron status after liver transplantation were investigated. A total of 450 liver transplant patients were enrolled in this study with a median follow-up of 37 months. Kaplan-Meier and Cox regression survival analyses showed a significantly worse graft survival for liver transplantation cases with an Hp 2-2 donor phenotype, which was associated with an increased mortality rate in this group. In male patients, the Hp 2-2 phenotype was associated with higher serum ferritin concentrations, which may be linked to the significantly increased likelihood of infectious complications in this phenotype. Liver transplant patients with Hp 1-1 and Hp 2-1 grafts had a better outcome probability than recipients of an Hp 2-2 graft, which may be explained by differences in iron metabolism induced by the Hp genotype of the graft.

Genetic Structure and Variation of Van Cats

To determine the genetic structure and variation of Van cats and some other cats, seven enzyme loci were examined using horizontal starch gel electrophoresis. ME bands were observed for the first time in cats. For the enzyme loci CA ( 1 ), SOD, GPI, and GOT, neither the individual Van cats nor the specimens of other cat species exhibited any variation. These enzymes presented identical bands, all of which were homozygous. With respect to the PGD, ME, and ESD loci, however, genetic variation was observed in all of the cats. Hence, three of the seven gene-enzyme systems (43%) were polymorphic with two alleles, contributing to an estimate of average heterozygosity of 0.33-0.49 for the Van cats. PGD was the most discriminatory among the three polymorphic loci. The phylogenetic tree indicated that the Van, Persian, Turkish Angora, and Turkish Tekir cats are distinct from Siamese and Bombay cats.

Genetic Variability inApurimacia dolichocarpa(Fabaceae), a Narrow Endemic Species of Córdoba Hills, Argentina

Apurimacia dolichocarpa (Fabaceae) is a narrow endemic species, restricted to Córdoba Hills, Argentina. At present, only two populations are known. In order to analyse the level and distribution of its genetic variability, allele frequencies in 16 loci coding for enzymes were estimated from starch gel electrophoresis patterns. The levels of genetic diversity (P99% = 56.25, A = 1.81, He = 0.1125) are higher than the mean for endemic species reported in the literature. The low level of genetic differentiation between the two populations (θ = 0.04) may be the result of a recent fragmentation of an ancestral panmictic population. Apurimacia dolichocarpa does not appear as threatened from the genetic viewpoint, given that its populations preserve a moderate level of allozymic polymorphism. Artificial establishment of intermediate populations would facilitate pollen dispersal, a strategy that could favour the maintenance of the polymorphism levels.

Association between milk protein polymorphism and milk production traits in Black and White dairy cattle in Turkey

Milk protein polymorphism such as as1-casein (as1-Cn), b-lactoglobulin (b-Lg), b-casein (b-Cn) and k-casein (k-Cn) of Black and White dairy cattle were investigated in this study. The genetic structure of herd was examined for these loci. At the sametime the relationships between milk protein types and some milk production traits were determined. Milk production traits were chosen as milk yield, average daily milk yield and lactation length. These traits were associated with milk protein types. Genetic variants of milk protein were identified by starch gel electrophoresis containing mercaptoethanol and urea. The allele gene frequencies of A, B, and C of as1-Cn loci and A, B of b-Cn were found to be 0.01; 0.97; 0.02 and 0.95; 0.05 respectively. Furthermore, the allele frequencies of A, B of k-Cn and A, B of b-Lg were found to be 0.68; 0.32 and 0.55; 0.45 respectively. For as1-Cn BB phenotype was found to have higher milk yield than those of as1-Cn AB and as1-Cn BC phenotypes, and b-Lg AA phenotype was detected to have higher milk yield than those of b-Lg AB and b-Lg BB types but were not statistically important. It was concluded that the genetic structure of the four loci were determined in Black and White cattle, but there was no significant association between the milk protein types and milk production traits in the study. Key words : Milk protein polymorphism, casein, lactoglobulin, Black and White dairy cattle.

Genetic analysis of silver-fir populations in the North Carpathian and Sudeten Mountains

Seeds collected from individual trees in the 16 Carpathian and 2 Sudeten silver-fir (&lt;em&gt;Abies alba&lt;/em&gt;) populations were studied with the starch gel electrophoresis in megagametophytes using 14 enzyme systems with 28 loci. The results show that the geographical distance between populations are in a small part reflected in genetic distances. There are two main groups of populations: Sudeten and Carpathian with a very big genetic distance between them. Other populations consist of a few small groups with low gene flow between them (&lt;em&gt;N&lt;sub&gt;m&lt;/sub&gt;&lt;/em&gt; = 3.286). About 80% of genetic variation is located within populations (&lt;em&gt;F&lt;sub&gt;ST&lt;/sub&gt;&lt;/em&gt; = 0.223). Average values for genetic multiplicity and diversity for Carpathian populations are as follows: number of alleles per locus: &lt;em&gt;Na&lt;/em&gt; = 2.308, with effective number of alleles &lt;em&gt;Ne&lt;/em&gt; = 1.552 and proportion of polymorphic loci 71.21%. The mean number of alleles per locus (&lt;em&gt;Na&lt;/em&gt;) varied from 2.107 to 2.607 in population. The mean effective number of alleles per locus (&lt;em&gt;Ne&lt;/em&gt;) ranged from 1.429 to 1.662. Average Fis for Carpathian populations was -0.021, which means that there is small excess of heterozygotes. The average observed heterozygosity amounted to &lt;em&gt;Ho&lt;/em&gt; = 0.275 and expected heterozygosity was &lt;em&gt;He&lt;/em&gt; = 0.269. The dendrogram structure and presence of rare alleles found in silver-fir of Czech, and Slovakian populations allow for a hypothesis that in postglaciation the silver-fir moved into the Polish Carpathians not westward from the east but from the south along river valleys from some Balkan refuges, getting North bypassing the High Tatra Range. This way, a highly diversified set of populations originated, differ in the presence of rare alleles. This differentiation is not prevented by a relatively small flow of genes between populations. The calculated gene flow &lt;em&gt;Nm&lt;/em&gt; = 3.286 also indicates isolation between the populations. It means 3.3 immigrants per generation into the studied populations.

ATATÜRK ÜNİVERSİTESİ KOYUN SÜRÜLERİNDE BETAGLOBULİN POLİMORFİZMİNİN GENETİĞİ VE KANTİTATİF KARAKTERLERLE BAĞLANTISI I. GENETİK ANALİZLER

.Ozet Starch-gel elekiroforez teknigi ile belirlenen TfA,TfB,Tfu,TfT>, ve TfE ergenlerinin sikliklari, sirasiyla Morkaramarida 0.341,0.161,0.222,0.266,0.010; Merinosuz 0.160,0.175, 0.277, 0.340, 0.048; IvesVde 0.269,0.355,0149,0.167, 0.060 olmustur. Transferrin genlerinin irklar arasindaki dagilislari onemli derecede, (P TfA/ TfD, TfA/ TfE, Tf*! TfM, Tf* Tfn, Tf*! TfMl Tfv, TfMi TfE, Tf°! TfE,) olmak uzere toplam 14 genotip ortaya cikarilmistir. Bunlardan TfMITfE tipi Morkaraman ve IvesVde, TfAjTfE tipi Merinos'da, TfEjTfE tipi ise irklarin hicbirinde gorulmemistir. Beta-globulin fenotiplerinin ampirik ve teorik dagilislari arasindaki farklar Morkaraman {kikare:42.2) ve Merinos*da (kikare: 30.7) cok onemli (P<0.001); IvesVde (kikare: 5.0) onemsiz olmustur. Yabanci damizliklara kapali suruler icinde hat gelistirilmis olmasi Hardy-Weinberg dengesinden uzaklasmanin nedeni olarak gorulmustur. Summary Genetics of Beta-Globulin Polymorphism and Its Association With Quanti tatve Characters in Ataturk University Flocks: I. Genetic Analysis 87 The frequencies for TfA,TfB,TfM,TfD and TfE which were typed by starch gel electrophoresis were 0.341,0.161,0.222,0.266,0.010 in Morkaraman; 0.160, 0.175,0.277,0.340,0.048 in Merino and 0.269,0.355,0.149,0.167, C.060 in Awassi ewes, respectively. The distribution of transferrin genes differed significantly (P<0.001) between the three breeds (chi-square; 79.1; d. f: 8). Gene fiequencies were significantly independent from the age of ewe arid culling did not affect beta- globulin locus. 4 homozygous (TfA/TfA,TfB/TfB, TfM/TfM, TfD/TfD) and 10 heterozygous (TfA/TfB,TfA/TiM,TfA/TfD, TfA/TfE,TfB/TfM,TfB/TfD, TP/Tf6, TfM/TfD, TfM/TfD/TiE) were determined in the flocks. The TfM/TfE, genotypes were not found in Morkaraman and Awassi ewes, while the TfE/TfE type was not observed in any of the breeds. Differences between empirical and theoretical distributions for beta-globulin phenotypes were significant (P<0.001) in Morkaraman (Chi-square: 42.2) and Merino (ch'-square: 30. 1) but notsignificant in Awassi (chi-square: 5.0). Significant departure from Hardy-Weinberg equilibrium was probably due to the facts that the flocks were closed to gene flow and the two inhered lines had been developed in Morkaraman and Merino ewes.

Monomorphism of isozyme loci in natural and cultivated amaranth (Amaranthus L.) populations

Starch gel electrophoresis was used for isozyme analysis of ADH, GDH, MDH, IDH, and ME in populations of amaranth. Experiments were performed with 93 populations and 4 cultivars. Some populations proved to be polymorphic, and this fact allowed analysis of the genetic control of the enzymes listed. The populations examined showed poor allozyme variability. Monomorphism for all loci studied was observed in 73 populations and 4 varieties. Starch gel electrophoresis was used for isozyme analysis ofADH, GDH, MDH, IDH, and ME in populations of amaranth. Experiments were performed with 93 populations and 4 cultivars. Some populations proved to be polymorphic, and this fact allowed analysis of the genetic control of the enzymes listed. The populations examined showed poor allozyme variability. Monomorphism for all loci studied was observed in 73 populations and 4 varieties. Only some populations demonstrated rare polymorphism for a single locus each: Adh, Mdh 2, Gdh, Idh 1, Idh 2, or Mod 2. The results demonstrate genetic monomorphism of amaranth for the studied loci.

Introgressive Hybridization between Bighead Carp and Silver Carp in the Mississippi and Illinois Rivers

AbstractAsian carps are classified as either bighead carp Hypophthalmichthys nobilis or silver carp H. molitrix by multiple presumptively diagnostic morphological characteristics; however, hybrids pose a dilemma. Fish sharing the morphological characteristics of both species were observed in an Illinois River backwater (Calhoun County, Illinois) approximately 5 mi (8 km) upriver from the confluence with the Mississippi River as well as in two locations in Pool 26 of the Mississippi River (Madison County, Illinois). Biopsied tissues from individuals exhibiting mixed morphological features were analyzed at four diagnostic allozyme loci (ADH‐1*, sMDH‐A*, CK‐A*, and sSOD‐1*) via starch gel electrophoresis. This comparison revealed a high percentage of hybridization (22.5%) from an indiscriminate sample of 120 fish. Moreover, an unexpected percentage (12.5%) of individuals identified in the wild as either parental bighead carp or silver carp by gill raker morphology were genetically identified as hybrids. Finally, two levels of hybridization were detected, first‐generation hybrids (F1) and post‐F1 hybrids, revealing the onset of extensive introgression and the potential for a hybrid swarm. Variation in the amplified COII domain of mitochondrial DNA indicated a strong directional bias of hybrids (88%) containing silver carp maternal lineages. Morphologically, F1 hybrids were often identifiable (88%) by the presence of twisted gill rakers, but post‐F1 hybrids were difficult to identify with any appreciable certainty. This result creates concern where taxonomic assignment is critical for management or monitoring, warranting a more extensive and intensive examination of this phenomenon in North American waters. Finally, prior observations in aquaculture have shown reduced jumping behavior, fitness, and condition of fish resulting from post‐F1 matings between these species. This is the first confirmed presence of wild post‐F1 individuals of Asian carps in the United States and, although further monitoring is needed, a hybrid swarm may ultimately decrease invasion success as introgression continues.

Genetic variation of Zoarces viviparus: six populations revisited after about 35 years

Totally, 417 eelpouts from six localities were collected in November-December 2007. Among these, 314 were females and from 246 of these females, one offspring was collected. The selected populations were also studied 36-38 years ago with the same technique, horizontal starch gel electrophoresis. The same enzymes were analysed at that time and now, but additional enzymes were analysed in the samples collected now, totally five enzymes representing 10 loci. A strong congruence in the genetic composition was found between the samples collected 36-38 years ago and those collected in 2007. No effect of pollutants in the environment was seen on the genetic variation by means of isozymes, but deformed offspring was observed and furthermore at one locality a high frequency of not pregnant females in the sample was observed.

Polymorphism of hordein-coding loci in cultivated barley (Hordeum vulgare L.) in Afghanistan

Polymorphism of hordeins encoded by the HrdA, Hrd B, and Hrd Floci was analyzed in 84 accessions of local barley (Hordeum vulgare L.) varieties from major agricultural regions of Afghanistan using starch gel electrophoresis. Forty alleles of the Hrd A locus with the frequencies from 0.12 to 32.73%, 62 alleles of the Hrd B locus with the frequencies from 0.12 to 14.29%, and five alleles of the Hrd Flocus with the frequencies from 0.59 to 32.15% have been identified. The conclusion about genetic similarity of barley populations from different regions of Afghanistan is made on the basis of cluster analysis of the matrix of allele frequencies in barley populations from 31 localities. The local barley populations form four unequal clusters. The largest cluster I includes populations from 14 localities of Afghanistan. The second largest cluster IV consists of populations from ten localities, and clusters II and III comprise populations from four and three localities, respectively. Each of the four clusters includes populations from different regions of northern and southern Afghanistan. Based on our results, we conclude that the diversity of hordein-coding loci and the distribution of their alleles among different regions of Afghanistan are the consequences of introduction of barley landraces and their distribution over trade routes.

Genetic diversity analysis of black locust (Robinia pseudoacacia L.) distributed in China based on allozyme markers approach

Using starch gel and polyacrylamide gel electrophoresis, the genetic diversity of 19 populations of black locust (Robinia pseudoacacia L.) distributed in China has been evaluated based on seven allozyme systems. Among the 14 enzyme loci studied, 12 of them showed polymorphic, giving a total of 40 alleles. The average allelic number (A) and the average effective allelic number (Ae) were 3.004 and 2.178, whereas the average of expected heterozygosity (He) and the observed heterozygosity (Ho) were 0.525 and 0.440, respectively. The total genetic differentiation (HT) in the 19 populations tested was 0.536, including 0.515 within population (HS) and 0.021 among populations (DST). The mean coefficient of genetic differentiation (GST) was 0.038, indicating that 3.8% of genetic differentiation was resulted from the populations, and the rest from those within the population. The genetic distance among the 19 populations was small, ranging from 0.015 to 0.065. Cluster analysis based on AVERAGE showed that populations with closer geographical distribution had higher genetic similarity than that in populations with far away distribution. There was no evident geographic differentiation pattern in Chinese black locust populations at a biochemical level.