comparative genomics ͉ radiation hybrid ͉ map integration D etailed whole-genome maps are a major currency for comparative and functional genomics (1). With the human, rat, and mouse genomes completely sequenced (2-6), eight mammalian genomes to follow with Ͼ6-fold coverage, and eight others to be sequenced in draft form (www.genome.gov͞10002154), greater insights into mammalian genome evolution and function can be obtained because of the improved accuracy and resolution of comparative maps (1). We previously reported two expressed sequence tag (EST)-based 5,000-rad cattle radiation hybrid (RH) maps containing 768 and 1,463 anchor points in the human genome, corresponding to Ϸ45% and 65% of comparative human genome sequence coverage, respectively (7, 8). These maps, collectively known as the Illinois-Texas 5,000-rad radiation hybrid panel (IL-TX RH 5,000 ) maps, facilitated the identification of genes responsible for double-muscling (9, 10), chondrodysplasia (11), and two major quantitative trait loci for milk production (12, 13).Recently, Itoh et al. (14) constructed a cattle-human comparative RH map consisting of 5,593 EST and microsatellite markers. This map contains 1,716 anchor points between the human and cattle genomes, of which most are ESTs, and was reported to have Ϸ72% comparative coverage of the human genome. A significant drawback of EST-based comparative maps is the uneven marker distribution that often results in relatively large gaps in comparative coverage. These gaps significantly complicate comparative genome analysis, especially around the evolutionary breakpoint regions. To overcome this limitation, we initiated the development of highresolution RH maps that use the sequenced ends of bacterial artificial chromosome (BAC) inserts as comparatively anchored markers (15). The BAC-end sequences (BESs) selected for mapping were linked by sequence similarity to the human and mouse genome sequences and were evenly spaced in the reference genomes at Ϸ1-Mbp intervals. The approach resulted in the construction of detailed comparative maps of BTA15 and BTA29, with Ϸ86% comparative coverage of HSA11 (15). Furthermore, the study revealed the presence of chromosome breakpoints that were ''reused'' in mammalian evolution, results that were recently confirmed in a more detailed multispecies analysis (1). Herein, we report extension of our methodology to mapping the whole cattle genome. The new map has Ϸ91% comparative coverage of the human genome sequence and contains single-linkage groups for all cattle autosomes. In addition, we used the new high-resolution cattle-human comparative map to study the evolution of centromeres and telomeres, conduct an analysis of gene content within evolutionary breakpoints, and demonstrate the power of the map for proofing the order of contigs in the physical map. MethodsMarker Selection and Mapping Strategy. BESs from the cattle male CHORI-240 (http:͞͞bacpac.chori.org͞bovine240.htm) BAC library were downloaded from GenBank and repeat-masked by using REPEATMASKER software (...
With the continuing increase of inclusive education in our public school classrooms today, there is a great deal of interest in co-teaching teams. Research indicates that administrative support is a critical factor in co-teaching effectiveness. In this study, we explored administrator knowledge and practices related to the supervision and evaluation of co-teachers in inclusive classroom settings. Clear themes that emerged were related to professional preparation and training; expectations and perspectives of co-teaching and inclusive practice; and supporting, supervising, and evaluating co-teachers. The data indicated that there is considerable inconsistency in administrator knowledge and practices and that professional development for administrators is warranted. Implications for practice as well as questions and issues for further research are discussed.
Summary The buffalo (Bubalus bubalis) is a source of milk and meat, and also serves as a draft animal. In this study, a 5000‐rad whole‐genome radiation hybrid (RH) panel for river buffalo was constructed and used to build preliminary RH maps for BBU3 and BBU10 chromosomes. The preliminary maps contain 66 markers, including coding genes, cattle expressed sequence tags (ESTs) and microsatellite loci. The RH maps presented here are the starting point for mapping additional loci that will allow detailed comparative maps between buffalo, cattle and other species whose genomes may be mapped in the future. A large quantity of DNA has been prepared from the cell lines forming the river buffalo RH panel and will be made publicly available to the international community both for the study of chromosome evolution and for the improvement of traits important to the role of buffalo in animal agriculture.
ABSTRACT:The buffalo (Bubalus bubalis) not only is a useful source of milk, it also provides meat and works as a natural source of labor and biogas. To establish a project for buffalo genome mapping a 5,000-rad whole genome radiation hybrid panel was constructed for river buffalo and used to build preliminary RH maps from two chromosomes (BBU 3 and BBU10). The preliminary maps contain 66 markers, including coding genes, cattle ESTs and microsatellite loci. The RH maps presented here are the starting point for mapping additional loci, in particular, genes and expressed sequence tags that will allow detailed comparative maps between buffalo, cattle and other species to be constructed. A large quantity of DNA has been prepared from the cell lines forming the RH panel reported here and will be made publicly available to the international community both for the study of chromosome evolution and for the improvement of traits important to the role of buffalo in animal agriculture.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.