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.
Resumen
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.
Por qué esto importa para la hirudoterapia
Este estudio evaluó la distinción genética entre aislados de laboratorio del género de sanguijuelas Helobdella —ampliamente utilizado en biología del desarrollo de anélidos— mediante la secuenciación del COI mitocondrial a partir de especímenes obtenidos de cultivos de laboratorio y sitios de campo. Los resultados revelaron que la comunidad investigadora ha trabajado sin saberlo con cinco especies distintas de dos clados principales, con aislados previamente asumidos como H. robusta que en realidad representan tres especies separadas, dos coexistiendo en la misma localidad. Los autores instan a los investigadores a preservar especímenes testigo y obtener códigos de barras moleculares. Para ASH, este estudio subraya un principio crítico relevante para cualquier campo basado en sanguijuelas: la identificación precisa de especies mediante códigos de barras moleculares es esencial, ya que la variación de especies crípticas podría confundir tanto la investigación como las aplicaciones terapéuticas por igual. Sin embargo, las especies de Helobdella son modelos de biología del desarrollo, no las sanguijuelas utilizadas en hirudoterapia; la relevancia del estudio es metodológica más que terapéutica.
Citación
Lessons from leeches: a call for DNA barcoding in the lab.
Bely AE, Weisblat DA · Evolution & Development, 2006
Contexto clínico relacionado
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Añadido a la biblioteca ASH: May 27, 2026 · Última actualización del sitio: 18 de junio de 2026