Lessons from leeches: a call for DNA barcoding in the lab
Methodology paper published in Evolution & Development (2006)
Abstract
Many evolution of development labs study organisms that must be periodically collected from the wild. Whenever this is the case, there is the risk that different field collections will recover genetically different strains or cryptic species. Ignoring this potential for genetic variation may introduce an uncontrolled source of experimental variability, leading to confusion or misinterpretation of the results. Leeches in the genus Helobdella have been a workhorse of annelid developmental biology for 30 years. Nearly all early Helobdella research was based on a single isolate, but in recent years isolates from multiple field collections and multiple sites across the country have been used. To assess the genetic distinctness of different isolates, we obtained specimens from most Helobdella laboratory cultures currently or recently in use and from some of their source field sites. From these samples, we sequenced part of the mitochondrial gene cytochrome oxidase I (COI). Sequence divergences and phylogenetic analyses reveal that, collectively, the Helobdella development community has worked on five distinct species from two major clades. Morphologically similar isolates that were thought to represent the same species (H. robusta) actually represent three species, two of which coexist at the same locality. Another isolate represents part of a species complex (the "H. triserialis" complex), and yet another is an invasive species (H. europaea). We caution researchers similarly working on multiple wild-collected isolates to preserve voucher specimens and to obtain from these a molecular "barcode," such as a COI gene sequence, to reveal genetic variation in animals used for research.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Резюме
Mitochondrial COI sequencing of Helobdella isolates from leading evolutionary-development labs over 30 years revealed five distinct species had been worked on as if they were one — including cryptic species, a species complex, and an invasive H. europaea.
Почему это важно для гирудотерапии
This study assessed genetic distinctness among laboratory isolates of the leech genus Helobdella—widely used in annelid developmental biology—by sequencing mitochondrial COI from specimens obtained from laboratory cultures and field sites. The results revealed that the research community has unknowingly worked on five distinct species from two major clades, with isolates previously assumed to be H. robusta actually representing three separate species, two coexisting at the same locality. The authors caution researchers to preserve voucher specimens and obtain molecular barcodes. For ASH, this study underscores a critical principle relevant to any leech-based field: accurate species identification through molecular barcoding is essential, as cryptic species variation could confound research and therapeutic applications alike. However, Helobdella species are developmental biology models, not the leeches used in hirudotherapy; the study's relevance is methodological rather than therapeutic.
Цитирование
Lessons from leeches: a call for DNA barcoding in the lab.
Bely AE, Weisblat DA · Evolution & Development, 2006
Связанный клинический контекст
Узнайте, как это исследование связано с клинической практикой
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