Determining Platypus Relationships

1995 ◽  
Vol 43 (3) ◽  
pp. 283 ◽  
Author(s):  
NJ Gemmell ◽  
TR Grant ◽  
PS Western ◽  
J Walmsley ◽  
JM Watson ◽  
...  

In the summer of 1990-91 the first captive breeding of platypus (Omithorhynchus anatinus) in 47 years, and only the second ever, occurred in a small resident population at Warrawong Sanctuary, South Australia. DNA fingerprinting and analyses employing the maternally inherited mitochondrial genome have been used to determine family relationships within this population Using hypervariable DNA sequences cloned from other species to probe blots of DNA from the Warrawong platypuses, individual-specific banding patterns have been observed that allow the identification of family relationships within the population. A novel method for detecting maternal relationships within platypus populations, based on polymerase chain reaction analyses of the highly polymorphic mitochondrial control region, is also presented.

Genome ◽  
1992 ◽  
Vol 35 (4) ◽  
pp. 621-626 ◽  
Author(s):  
Peter M. Rogowsky ◽  
Ken W. Shepherd ◽  
Peter Langridge

A novel type of polymerase chain reaction (PCR) marker was developed for the mapping of cereal rye (Secale cereale). Primer pairs were synthesized targeting the insertion sites of three individual copies of the R173 family of rye specific repeated DNA sequences. While one primer was derived from a sequence within the respective R173 element, the second primer corresponded to a flanking region. The complex banding patterns obtained in rye allowed not only the mapping of the three R173 elements to certain chromosome regions of 1RS (the short arm of rye chromosome 1) but also the mapping of an additional 3–10 easily identifiable bands per primer pair to other rye chromosomes. Linkage mapping of a polymorphic 1R band derived from three rye cultivars demonstrated the presence of nonallelic, dominant markers in two independent crosses. Because of the high copy number of the R173 family (15 000 copies per diploid rye genome), its dispersion over the entire length of all chromosomes and the high number of markers obtained per primer pair, PCR markers based on the R173 family provide an almost unlimited source for well-spaced markers in rye mapping.Key words: polymerase chain reaction, mapping, repetitive DNA sequences, wheat, rye.


2014 ◽  
Vol 104 (3) ◽  
pp. 233-237 ◽  
Author(s):  
María José Iglesias Sánchez ◽  
Ana María Pérez Pico ◽  
Félix Marcos Tejedor ◽  
María Jesús Iglesias Sánchez ◽  
Raquel Mayordomo Acevedo

Background Dermatomycoses are a group of pathologic abnormalities frequently seen in clinical practice, and their prevalence has increased in recent decades. Diagnostic confirmation of mycotic infection in nails is essential because there are several pathologic conditions with similar clinical manifestations. The classical method for confirming the presence of fungus in nail is microbiological culture and the identification of morphological structures by microscopy. Methods We devised a nested polymerase chain reaction (PCR) that amplifies specific DNA sequences of dermatophyte fungus that is notably faster than the 3 to 4 weeks that the traditional procedure takes. We compared this new technique and the conventional plate culture method in 225 nail samples. The results were subjected to statistical analysis. Results We found concordance in 78.2% of the samples analyzed by the two methods and increased sensitivity when simultaneously using the two methods to analyze clinical samples. Now we can confirm the presence of dermatophyte fungus in most of the positive samples in just 24 hours, and we have to wait for the result of culture only in negative PCR cases. Conclusions Although this PCR cannot, at present, substitute for the traditional culture method in the detection of dermatophyte infection of the nails, it can be used as a complementary technique because its main advantage lies in the significant reduction of time used for diagnosis, in addition to higher sensitivity.


2001 ◽  
Vol 125 (3) ◽  
pp. 347-352
Author(s):  
Kazuya Yamashita ◽  
Tsutomu Yoshida ◽  
Hiroshi Shinoda ◽  
Isao Okayasu

Abstract Background and Objective.—Abnormal protein expression and gene mutation should be examined on exactly identified lesions. To perform simultaneous analyses of oncogene or tumor suppressor gene mutations and related protein expression in single histologic sections, we have developed a novel method using an antigen-retrieval solution for a polymerase chain reaction template before immunohistochemical staining. Methods.—Using 20 cases of sporadic colorectal carcinoma, several kinds of antigen-retrieval solutions were tested after heating rehydrated, 4-μm-thick, formalin-fixed, paraffin-embedded histologic sections at 96°C for 20 minutes. Polymerase chain reaction–single-strand conformation polymorphism analysis was conducted for p53 (exons 5 through 9) and K-ras (exons 1 and 2), and the histologic sections were then immunostained with monoclonal antibody against p53. Results.—DNA analysis of antigen-retrieval solutions was possible in all 20 cases and revealed completely consistent results (100%) with fresh cancer tissue and microdissected cancer tissue of paraffin-embedded histologic sections. With this method, K-ras mutations were positive in 10 of 20 cases (exon 1 in 9 cases and exon 2 in 1 case) and p53 mutations were positive in 9 of 20 cases (exon 5 in 4 cases, exon 6 in 1, exon 7 in 3, and exon 8 in 1 case), with 8 of the 9 p53 mutation cases showing diffuse p53 protein expression on immunostaining. Base alterations of all abnormal conformers were confirmed with direct sequencing. For polymerase chain reaction–single-strand conformation polymorphism analysis, sodium citrate buffer (pH 6.0) was found to be the optimal antigen-retrieval solution. Conclusions.—This newly developed method can be used for routine immunostaining and genetic analysis with single histologic sections.


Genetics ◽  
1994 ◽  
Vol 137 (1) ◽  
pp. 95-106 ◽  
Author(s):  
D Cassidy-Hanley ◽  
M C Yao ◽  
P J Bruns

Abstract A method for mapping DNA sequences to specific germinal chromosomes in the ciliated protozoan Tetrahymena thermophila has been developed. This mapping technique (PCR mapping) utilizes the polymerase chain reaction and template DNA derived from nullisomic strains to directly assign micronuclear DNA sequences to specific micronuclear chromosomes. Using this technique, a number of unique sequences and short repetitive sequences flanked by unique sequences have been mapped to four of the five germinal chromosomes.


2007 ◽  
Vol 18 (04) ◽  
pp. 899-910 ◽  
Author(s):  
SUDHA BALLA ◽  
SANGUTHEVAR RAJASEKARAN ◽  
ION I. MANDOIU

Degenerate primers are used to amplify a given set of genomic sequences using a technique called Multiplex Polymerase Chain Reaction (MP-PCR). The problem of minimizing the number of degenerate primers required to amplify a given set of DNA sequences, also known as the Degenerate Primer Design Problem (DPDP), has been extensively studied in the literature and proven to be NP-Complete. In this paper we present efficient algorithms for solving DPDP. For example, one of the algorithms we give in this paper is iterative and has a runtime of O(b|Σ|log|Σ|dn2mp) to select a set of p degenerate primers, each of given length l and degeneracy at most d, for n sequences each of length m in the input, the number of candidates retained in each iteration being b. Σ is the alphabet of the input strings. This is an improvement over the runtime of the best known prior algorithm, MIPS by Souvenir et al. [15], which has a runtime of O(bn3mp). We provide an experimental comparison of MIPS and our algorithms.


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