Data for: Estimation of genetic parameters for the implementation of selective breeding in commercial insect production
Data files
Mar 20, 2024 version files 1.13 MB
Abstract
Background
There is a burgeoning interest in using insects as a sustainable source of food and feed, particularly by capitalising on various waste materials and by-products that are typically considered of low value. Enhancing the commercial production of insects can be achieved through two main approaches: optimising environmental conditions and implementing selective breeding strategies. In order to successfully target desirable traits through selective breeding, having a thorough understanding of the genetic parameters pertaining to those traits is essential. In this study, a full-sib half-sib mating design was used to estimate variance components and heritabilities for larval size and survival at day seven of development, development time and survival from egg to adult, and to estimate correlations between these traits, within an outbred population of house flies (Musca domestica), using high-throughput phenotyping for data collection.
Results
The results revealed low to intermediate heritabilities and positive genetic correlations between all traits except development time and survival to day seven of development and from egg to adulthood. Surprisingly, larval size at day seven exhibited a comparatively low heritability (0.10) in contrast to development time (0.25), a trait that is believed to have a stronger association with overall fitness. A decline in family numbers resulting from low mating success and high overall mortality reduced the amount of available data which resulted in large standard errors for the estimated parameters. Environmental factors made a substantial contribution to the phenotypic variation, which was overall high for all traits.
Conclusions
There is potential for genetic improvement in all studied traits and estimates of genetic correlations indicate a partly shared genetic architecture among the traits. All estimates have large standard errors. Implementing high-throughput phenotyping is imperative for the estimation of genetic parameters in fast developing insects, and facilitates age synchronisation, which is vital in a breeding population. In spite of endeavours to minimise non-genetic sources of variation, all traits demonstrated substantial influences from environmental components. This emphasises the necessity of thorough attention to the experimental design before breeding is initiated in insect populations.
README: Dataset: Estimation of genetic parameters for the implementation of selective breeding in commercial insect production
https://doi.org/10.5061/dryad.kwh70rzc5
Housefly (Musca domestica) phenotype data. Data was collected in the autumn/winter 2021 by Laura Skrubbeltrang Hansen (AU, QGG, Denmark) and Stine Frey Laursen (AAU, Denmark) in the DFF FTP project "Optimisation of insect production for animal feed through breeding" (Torsten Nygaard Kristensen, AAU, Denmark). There are four traits in the dataset: larval size (surface area of larvae at day 7 of development), larval survival (survival from egg to day 7 of development), development time (time from egg until emergence as adult) and adult survival (survival from egg to the day of emergence as adult). The traits are recorded on offspring from a number of full- and half-sib families. The dataset has 19800 observations and 20 variables. Many observations are NA.
Description of the data and file structure
A nested paternal full-sib half-sib design was used when generating the house fly families in this experiment. There is a total of 94 mating groups (94 males each given 5 females for mating). Twenty eggs (twenty rows in the excel file) from each female were designated for the measurement of larval traits, and 20 eggs were designated for the measurement of adult traits, ensuring that all traits were recorded on full siblings. Eggs were always collected from the same oviposition event and if a female oviposited enough eggs for the measurement of larval traits only, then no eggs were collected to measure adult traits. If more than 60 eggs were collected from a female, 20 eggs were designated for a third group of full siblings (not included in this study). The time from isolation until a female oviposited (time-to-oviposition, ±12 hours) was registered for all females. Since the eggs are vulnerable to damage and drying out during the handling process, the observer handling the eggs (observer) was registered for all eggs and thus, the effect of the observer can be tested on all traits recorded on the offspring.
Column descriptions:
id: 5-6 digit number consisting of sire ID, dam ID and individual ID. Example: (0)10516 is sire 01, dam 05 (nested within sire) and individual 16. There are five dams per sire and 40 offspring per dam.
sireid: 5-6 digit number consisting of sire ID followed by "0000". Example: 460000 is sire 46.
damid: 5-6 digit number consisting of sire ID, dam ID and "00". Example: (0)80200 is dam 02 mated to sire (0)8.
vial: Either 1 or 2. 1 = full-sibs reared for recording of larval traits. 2 = full-sibs reared for recording of adult traits. Vial is nested within dam-id (up to two groups of offspring are established for every egg-laying dam).
replicate: number indicating population replicate (1,2,3)
medium: number indicating rearing substrate for offspring (1 = standard medium with alfalfa, in this dataset no other substrate is included)
damage: age of dam at time of mating (1 = 10 days. 2 = 14 days)
sex: sex of offspring (1 = female, 2 = male). Only recorded for offspring 21-40 for each dam. 0 indicates NA.
egg_obs: a number indicating the lab personnel who handled the offspring at the egg stage (egg counting). Variable can be used to account for any observer effect. Takes values 1-6. 0 indicates NA.
time_to_egg: the time (in hours) it took for the dam to oviposit after mating. Takes any value devisable by 12. 0 indicates NA.
date_egg: the date of dam oviposition (DDMMYY). 0 indicates NA.
time_egg: the time of day of dam oviposition (6 = 6AM, 18 = 6PM).
comb_obs: Observations from three out of six observers with the fewest records were combined under one observer label to avoid unbalanced group sizes in the dataset. Takes values 1-4 (4 is a combination of egg observer 4-6). 0 indicates NA.
comb_time: Due to the small numbers of eggs oviposited more than 24 hours after isolation, the records were grouped in two levels (two levels: 12 = eggs oviposited after 12 hours, 13 = eggs oviposited after more than 12 hours). 0 indicates NA.
comb_obs_time: A combination of comb_obs and comb_time. 8 levels. Example: 112 = observer 1 and eggs after 12 hours, 113 = observer 1 and eggs after > 12 hours. Remaining levels are 212,213,312,313,412,413 for observers 2-4. 0 indicates NA.
unknown: this variable separates the individuals with larval size records into two groups: 1 = larvae measured at <18.999 mm2 in size. 2 = larvae measured at >18.999 mm2 in size. 0 indicates NA.
Traits:
lar_size: continuous trait. Surface area of individual larvae measured at day 7 of development (unit is mm2). The trait is recorded only for offspring 1-20 for each dam and these individuals were sacrificed before reaching adulthood (so no record for adult survival exist for them). -9999 indicates NA (there are many NA's in this data since many dams never produced eggs. This offspring, that never existed, are still included in the dataset for practical purposes).
lar_via: the trait "larval survival" is a binary record for each offspring in the dataset. 1 = survived to day 7 (which is at the larval stage), 0 = did not survive to day 7. The trait is recorded only for offspring 1-20 for each dam and these individuals were sacrificed before reaching adulthood (so no record for adult survival exist for them). -9999 indicates NA (there are many NA's in this data since many dams never produced eggs. This offspring, that never existed, are still included in the dataset for practical purposes).
dev_time: discrete trait. Time (in hours) from egg until emergence as adult. Vials were checked for newly emerged adults every 12 hours. The trait is recorded only for offspring 21-40 for each dam (and no record of larval survival exist for them). -9999 indicates NA (there are many NA's in this data since many dams never produced eggs. This offspring, that never existed, are still included in the dataset for practical purposes).
adu_via: the trait "adult survival" is a binary record for each offspring in the dataset. 1 = survived to adulthood, 0 = did not survive to adulthood. The trait is recorded only for offspring 21-40 for each dam (and no record of larval survival exist for them). -9999 indicates NA (there are many NA's in this data since many dams never produced eggs. This offspring, that never existed, are still included in the dataset for practical purposes).
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