Number Of Founders Research Articles

Genetic study of an isolated population of adders Vipera berus founded by historic translocation: implications for conservation

Adder Vipera berus populations in Great Britain have undergone substantial declines in recent decades. Isolation due to habitat fragmentation particularly threatens the demographic and genetic health of small populations. Despite the potential benefit of population supplementation in the conservation management of affected populations, there are currently no consensus guidelines for conservation-motivated translocations of this species. Translocations of adders for ecological mitigation of land development are more frequently undertaken, although these are typically poorly documented and insufficiently monitored, representing a wasted opportunity for strategic learning and improvements. We studied an isolated adder population on a protected site in eastern England, founded in 1999 by the translocation of adders from a development site. With known numbers, age and sex of released individuals, this represented an opportunity to improve our understanding of the genetic outcome of a newly created population. Although apparently thriving despite a low founder number, the finding in 2015 of a stillborn clutch of adders raised the possibility of inbreeding in the population. We sampled adders from the translocated population in 2017, and two individuals from the donor site in 2018. Although we found no increase in homozygosity, relatedness and maximum likelihood sibship analysis revealed high levels of consanguinity, especially within the subgroup of adults. Demographic modelling with Approximate Bayesian Computation supported the known origin of the population, but also a subsequent, undocumented adder release to the site, accounting for the observed healthy proportion of young adders with lower levels of consanguinity. Despite the protected habitat site, the population remains isolated, and thus demographically and genetically vulnerable. We highlight the importance of careful post-translocation monitoring including targeted genetic analyses. Strategic data gathering coupled with careful management of translocations, whether for ecological mitigation or conservation rescue, could support significant improvements to the conservation management of this species, including reintroduction initiatives. Keywords: relatedness, inbreeding, stillbirth, foundation bottleneck, population supplementation

Pedigree-based analysis of population structure and genetic diversity in high-milch Vrindavani crossbred cattle of India.

The present study aimed to elucidate the population structure and genetic diversity along with the estimation of genealogical parameters in Vrindavani cattle using pedigree data. The study was based on pedigree data on 12,718 animals, spread across multiple generations during a 52-year period (between 1971 and 2023). The pedigree data was used to estimate different population genealogical parameters including the generation interval; pedigree completeness; rate and level of inbreeding; effective population size; and parameters characterizing the probabilities of gene origin. The ENDOG program was used for estimation of different parameters while using population after 2010as reference cohort. The results revealed the maximum number of generations (MG) to be 13, while the numbers of completed (CG) and equivalent generations (EqG) were 3.23 and 1.95, respectively. The mean generation interval for the population was 6.9years. The average inbreeding coefficient of animals in the whole and reference population was 1.11 and 3.44%, respectively; with 0.68% rate of inbreeding per generation. The average additive relationship among all the animals and those in the reference population was 1.16 and 5.49%, respectively. The average effective population sizes for the maximum, equivalent, and complete generations were 115.56, 56.42, and 46.02, respectively. The effective population size on the basis of regression and log-regression on birth date was 77.40 and 71.24, respectively. The probabilities of gene origin were estimated by the effective number of founders (fe) and ancestors (fa), which was 115 and 78, respectively. The fe/fa ratio in the reference population was 1.20, indicating that occasional bottlenecks may have occurred in the population. The analysis revealed a loss of 5.3% of total heterozygosity as compared to base population, though significant variability exists in the latest generations. The results revealed that considerable genetic variability exists within the population that may be exploited through appropriate breed improvement programs targeting various economic traits.

Successful reintroduction of the European pond turtle Emys orbicularis with a small number of founders: results from a 20-years small-scale experiment

Successful reintroduction of the European pond turtle Emys orbicularis with a small number of founders: results from a 20-years small-scale experiment

Population structure and genetic diversity in males of the autochthonous Busha cattle in Croatia

Busha is recognized as the most numerous autochthonous cattle breed in Croatia. In small populations, using the same sire repeatedly can increase inbreeding rates. This can lead to fewer high-quality, and high inbred breeding sires over time. Genealogical records of the Busha cattle breed registered from 1987 to 2022 were used to investigate the population structure and the genetic variability of the male individuals. The dataset included 10,411 animals, of which 3,962 were males. The average equivalent complete generation reached 2.92 in the total population and 3.05 in the reference population, when considering only living animals. The average inbreeding coefficient in the male population was 1.59%. Over the studied period, inbreeding rose to an average value of 2.07% in the last birth year cohort (2017-2022). The unequal contribution of the effective number of founders indicates the more frequent use of particular breeding sire lines. Nevertheless, despite the controlled inbreeding rate observed among breeding sires, and the absence of any evident population bottleneck, our study highlighted the need for breeding strategies to optimize the contribution of breeding animals in the next generations to ensure long-term conservation of the Busha cattle breed.

Elucidating population structure and genetic diversity of intercross sheep through pedigree analysis

The aim of this study was to assess the population structure and genetic diversity along with determining the accuracy of ongoing selection program in a closed flock of Intercross sheep through pedigree analysis. The pedigree records of 2245 animals maintained at CSWRI-NTRS, Garsa, Kullu during the period from 2012 to 2023 were utilized to calculate the genealogical information, genetic conservation index and other parameters based on gene origin probabilities. Lambs born during 2020 and 2023 were considered as reference population. ENDOG version 4.8 software package was used for pedigree analysis. Analysis revealed that the mean generation interval for the reference population was 3.20 years with a longer interval in dam-offspring pathways relative to sire-offspring pathways. Average inbreeding coefficients for whole and reference population were 0.21 and 0.49 % and corresponding average relatedness was 1.24 and 1.72 %, respectively. The average maximum, equivalent and completed generations were 2.50, 1.96 and 1.63 with 0.12 %, 0.17 % and 0.20 % increase in inbreeding coefficient, respectively. This resultant effective population size estimated using individual increase in inbreeding was 156.52. Effective numbers of founders (fe) and ancestors (fa) was 68 and 61, respectively for reference population with a ratio of 1.11, indicating occurrence of minor effects of bottleneck in the flock. The genetic contribution of most influent ancestors contributing 50 % of the gene pool was only 23. The estimated founder genome (fg) and non-founder genome (fng) were 35.87 and 75.91, respectively in the present population. The estimate for fg/fa ratio was 0.59 which explained that 59 % of the original genetic diversity is exit in the reference population. Genetic conservation index (GCI) ranged from 1 % to 20.28 % with a mean value of 4.91 %. Overall, males recorded a slightly higher GCI than females, i.e., 5.23 vs 4.65 %, respectively. The results revealed that, the population has augmented genetic diversity and low level of inbreeding. Small fraction of genetic diversity was vanished due to unequal contribution of founders and minor bottleneck effects occurred due to disproportionate contribution of breeding animals to gene pool of population. Use of a sufficient number of breeding rams and optimum contribution selection (OCS) is recommended to maintain the genetic diversity as well as enhancing production potential in this population.

Serial founder effects slow range expansion in an invasive social insect

Invasive populations often experience founder effects: a loss of genetic diversity relative to the source population, due to a small number of founders. Even where these founder effects do not impact colonization success, theory predicts they might affect the rate at which invasive populations expand. This is because secondary founder effects are generated at advancing population edges, further reducing local genetic diversity and elevating genetic load. We show that in an expanding invasive population of the Asian honey bee (Apis cerana), genetic diversity is indeed lowest at range edges, including at the complementary sex determiner, csd, a locus that is homozygous-lethal. Consistent with lower local csd diversity, range edge colonies had lower brood viability than colonies in the range centre. Further, simulations of a newly-founded and expanding honey bee population corroborate the spatial patterns in mean colony fitness observed in our empirical data and show that such genetic load at range edges will slow the rate of population expansion.

Pedigree-Based Genetic Diversity in the South African Boerboel Dog Breed.

The Boerboel dog breed (BBD) is indigenous to South Africa (SA) and plays an important role in safeguarding homes and farms. The Department of Agriculture, Land Reform, and Rural Development (DALRRD) classifies the BBD as a protected species, and it is valued for its intelligence, boldness, and strength, as well as for continually ensuring the safety of its owners. The aim of this study was to investigate genetic diversity within the BBD population using pedigree information. The original BBD data, which contained 87,808 records, were obtained from the Integrated Registration and Genetic Information System (INTERGIS). After editing, the pedigree data included 87,755 records of animals born between 1971 and 2019. Pedigree analyses were performed using PEDIG (Fortran 77 software) to determine the completeness, inbreeding coefficients, and genetic diversity as defined by the genetic contributions of the most important ancestors of the current animals. This study identified 91.2% inbred animals in the BBD population, with an average and maximum inbreeding of 7.5% and 50% of inbred animals, respectively. The estimated inbreeding rate per year was 0.20% with an effective population size of 83.1. The most influential ancestors explained 82.63% and 80.92% of the total genetic variation for males and females in the studied populations, respectively. Only 10 important ancestors explained more than 50% of the entire population's genetic diversity. The numbers of founders (f) were 348 and 356, and the effective numbers of founders (fe) were 57.4 and 60.1, respectively, for males and females. The numbers of founders were higher than the effective numbers of founders, implying a loss of genetic diversity due to unequal founder contributions. The BBD population was not critically endangered based on the inbreeding rates and effective population size; however, the population experienced a significant loss of genetic variability, unequal genetic contributions by founders, and a genetic bottleneck. Future breeding strategies could benefit from using equal proportions of parent stock and including new genetically distant breeds.

Population structure and genetic diversity of Polish Arabian horses based on pedigree data

With a history tracing back to at least the 18th century and a substantial global influence on various breeds, Polish Arabian horse population is of paramount importance for both breeders and conservationists. However, its genetic makeup and the population dynamics are still not well understood. This study presents an analysis of the modern Polish Arabian horse population using pedigree data, focusing on the breed's genetic diversity and population structure. Our analysis encompassed 1 498 individuals defined as the reference population (RP) and their 11 065 ancestors, which resulted in the dataset of 12 254 individuals (total population). We traced their genealogy to assess inbreeding coefficients (F), founder effects, and genetic variability measures such as the effective number of founders (fe), ancestors (fa), or founder genome equivalents (fge). The results indicated a good pedigree quality with an average of 28.1 maximum traced generations, revealing high pedigree completeness for initial generations with a decline beyond the seventh generation. The genetic diversity parameters showed a considerable bottleneck effect, with an effective number of founders at 73, which reflects a substantial loss of genetic diversity over time. Despite the vast total number of founders (852), only a few have had a lasting impact on the current population, signaling the need for revised breeding strategies to maintain diversity. The study identified a slight but consistent rise in inbreeding over the last century, with a marginal recent decline, and a significant difference in the contribution of various founders. The average F was 5.8%, with 99.6% of the reference population being inbred. The analysis of effective population size (Ne) highlighted potential risks for genetic diversity, urging for revision of breeding goals to consider a wider array of founder lineages. The study indicated that stallions belonging to RP can be attributed to 15 distinct sirelines, whereas mares to 45 unique damlines, more than considered in the current breeding program (8 and 15, respectively). Conclusively, the study underlines the need for ongoing monitoring and strategic breeding to maintain and enhance the genetic diversity of Polish Arabians, considering the breed's historical significance and contemporary genetic challenges.

Evaluation of the Impact of Population Management on the Genetic Parameters of Selected Spiral-Horned Antelopes.

The rapid loss of biodiversity and the associated reduction and fragmentation of habitats means that ex situ populations have become an important part of species conservation. These populations, which are often established from a small number of founders, require careful management to avoid the negative effects of genetic drift and inbreeding. Although the inclusion of molecular data is recommended, their availability for captive breeding management remains limited. The aim of this study was to evaluate the relationship between the levels of genetic diversity in six spiral-horned antelope taxa bred under human care and their respective management strategies, conservation status, demography, and geographic origin, using 10 nuclear DNA microsatellite loci and mitochondrial control region DNA sequences. Our findings include associations between genetic diversity and management intensity but also with the diversity and contribution of wild populations to captive founders, with some populations apparently composed of animals from divergent wild lineages elevating captive genetic diversity. When population sizes are large, the potential advantages of maximizing genetic diversity in widely outcrossed populations may need careful consideration with respect to the potential disruption of adaptive diversity. Genetic data serve as a robust tool for managing captive populations, yet their interpretation necessitates a comprehensive understanding of species biology and history.

Pedigree analysis in the mhorr gazelle (Nanger dama mhorr): Genetic variability evolution of the captive population.

Breeding programs have an essential role in the recovery of threatened populations through optimal genetic management and mating strategies. The dama gazelle (Nanger dama) is a North African ungulate listed as critically endangered. The mhorr subspecies is extinct in the wild and currently survives thanks to the creation in 1971 of an ex situ breeding program. The aim of the present study was to assess the evolution of genetic variability in this mhorr gazelle captive population, as well as the mating strategy used in two reference populations studied (Almeria and Europe). The entire pedigree, with 2739 animals, was analyzed to measure demographic characters, pedigree completeness level, probability of gene origin, level of relatedness and genetic structure of the population. The population size has been progressively increasing, with up to 264 individuals alive in Europe at the time of the study. The average number of equivalent complete generations was 5.55. The effective number of founders and ancestors was both 3, and the founder genome equivalent was 1.99. The genetic contributions of the four main ancestors were unbalanced. The average values of inbreeding and average relatedness for the whole pedigree were, respectively, 28.34% and 50.14%. The effective population size was 8.7 by individual increase in inbreeding and 9.8 by individual increase in coancestry. F-statistics evidenced a very small level of population subdivision (F ST = 0.033370). The mating strategy used, based on the minimum coancestry of the individuals, has minimized the losses of genetic variability and helped to balance the genetic contributions between ancestors. The strategy also avoided large subdivisions within the population and the appearance of new bottlenecks. This study shows how pedigree analysis can both be used to determine the genetic variability of the population and to assess the influence of the mating strategy used in the breeding program on such variability.

Colony level fitness analysis identifies a trade-off between population growth rate and dauer yield in Caenorhabditis elegans

BackgroundIn the evolution from unicellular to multicellular life forms, natural selection favored reduced cell proliferation and even programmed cell death if this increased organismal fitness. Could reduced individual fertility or even programmed organismal death similarly increase the fitness of colonies of closely-related metazoan organisms? This possibility is at least consistent with evolutionary theory, and has been supported by computer modelling. Caenorhabditis elegans has a boom and bust life history, where populations of nematodes that are sometimes near clonal subsist on and consume food patches, and then generate dauer larva dispersal propagules. A recent study of an in silico model of C. elegans predicted that one determinant of colony fitness (measured as dauer yield) is minimization of futile food consumption (i.e. that which does not contribute to dauer yield). One way to achieve this is to optimize colony population structure by adjustment of individual fertility.ResultsHere we describe development of a C. elegans colony fitness assay, and its use to investigate the effect of altering population structure on colony fitness after population bust. Fitness metrics measured were speed of dauer production, and dauer yield, an indirect measure of efficiency of resource utilization (i.e. conversion of food into dauers). We find that with increasing founder number, speed of dauer production increases (due to earlier bust) but dauer yield rises and falls. In addition, some dauer recovery was detected soon after the post-colony bust peak of dauer yield, suggesting possible bet hedging among dauers.ConclusionsThese results suggest the presence of a fitness trade-off at colony level between speed and efficiency of resource utilization in C. elegans. They also provide indirect evidence that population structure is a determinant of colony level fitness, potentially by affecting level of futile food consumption.

The Weight of Genetic Drift: A Pedigree-Based Evaluation of the Breton Horse Population in Brazil.

The genetic diversity of Breton horses in Brazil is a critical concern, mainly due to the small population size and low number of births per year. Given that the inbreeding was overlooked by breeders for multiple generations, we estimated the genetic diversity of this population utilizing pedigree-based measures of population diversity. A total of 1394 six-generation pedigrees representing the full population of registered Breton horses in Brazil defined a total population (TP, N = 2679), with horses born between 2000 and 2022, reproductively active and alive, as reported by the breed association, representing the reference population (RP, N = 731). Using the R package PurgeR, we estimated inbreeding coefficient (F ped ), maternal inbreeding coefficient (F da m ), paternal inbreeding coefficient (F sire ), individual reproductive values, number of equivalents to complete generations (t), and unbiased ancestral inbreeding coefficient (Fa). We established the equivalent complete generations (ECG), effective population size (Ne), total number of founders (Nf), effective number of founders (Nfe), total number of ancestors (Na), effective number of ancestors (Nae), founder genomes (Ng), and the inbreeding coefficient estimated with effective population size (Ne) and generation numbers (t) (F Ne:t ), as well as Nfe/Nae and Nfe/Ng ratios for the RP. The RP inbreeding levels have stabilized, although they are still significantly rising by generation (t), and the Nfe/Ng ratio strongly suggests genetic drift. Pedigree-based analysis demonstrates that only five stallions have sired 52.83% of the RP individuals, which along with the Nae value of 36.73 implies that the observed inbreeding can be arising from patrilines. Our results suggest that observed inbreeding is due to Popular Sire Effect, highlighting the importance of monitoring breeding schemes and genetic diversity to maintain health.

Designing, implementing and monitoring the translocation of a highly threatened freshwater fish

Abstract Conservation translocations are increasingly applied for the protection of threatened species, but their success depends strongly on pre‐release preparatory work and strict implementation methodology, followed by post‐release monitoring. The aim of this work was to implement a conservation translocation that involved (a) the design and application of a pre‐release feasibility assessment tool for the selection of the translocation water bodies; (b) the translocation of 77 individuals of the highly threatened freshwater Corfu killifish Valencia letourneuxi in 2015, 2016 and 2017; and (c) a 5‐year post‐release monitoring with multiple methods. After initial pre‐screening, a feasibility assessment was conducted on two potential release water bodies (R‐WBs) and on four potential source water bodies (S‐WBs), using a custom‐made feasibility assessment tool that incorporated 14 criteria for the potential R‐WBs, related to the species' habitat requirements, human pressures and technical issues. Two criteria were applied to the potential S‐WBs, on source population availability and on its genetic compatibility to the release area. Post‐release monitoring (2017–2022) was conducted with fish sampling methods, underwater video recording and/or using environmental DNA (eDNA). The feasibility assessment tool gave one R‐WB high, positive score, and one S‐WB met both criteria, thus these selected as the translocation water bodies. Despite the low number of founders, the establishment of a self‐reproducing population was finally confirmed in 2022 in the R‐WB, initially with video recording and subsequently by fish sampling and eDNA. This study highlights the importance of pre‐release feasibility assessment, the use of multiple post‐release monitoring methods and actions to secure the long‐term viability of the translocated population. The feasibility assessment tool and the methodological protocol can easily be modified for successful application to other freshwater fish species, with different habitat requirements, current and future human pressures and genetic constraints.

Genetic impact of external Targhee sires at the U.S. Sheep Experiment Station: a case study of introgression.

Sheep breeders requested that the U.S. Sheep Experiment Station (USSES) to participate in national genetic evaluation through the National Sheep Improvement Program (NSIP). The reasons included the need for (1) a comparison of the productivity of industry and United States Department of Agriculture (USDA) lines, (2) transparency of USDA flocks, (3) genetic ties for NSIP by sampling of industry flocks, and (4) development of premium genetic lines for public release. In response, USSES began to incorporate external sires from NSIP participating flocks into the USSES Targhee flock. Our objective, based on a pedigree analysis, was to test if introgression of external genetics into the flock was achieved. The pedigree included 13,189 animals with mean maximum generations, mean complete generations, and mean equivalent complete generations of 4.2, 1.8, and 2.6, respectively. The mean generation interval was 3.1 yr. The reference population was defined as lambs born from 2021 to 2023 (n = 792). Two additional populations were defined as the current mature ewe flock (n = 123) and the current mature rams (n = 14). The Genetic Conservation Index averaged 7.7 for the full population and 25.7 for the reference population. Overall inbreeding was 0.003 for the full population and 0.006 for the reference population. The rate of inbreeding was 0.0003 per generation. Average relatedness was 0.015 for the full population and 0.018 for the reference population. The effective number of founders, effective number of ancestors, and founder genome equivalents contributing to the reference population were 60, 39, and 19.1, respectively. The ratio of the effective number of founders to the effective number of ancestors was 1.5, indicating the presence of genetic bottlenecks. Measures of effective population size ranged from 102 to 547. Of the 704 offspring produced by external sires, 17 ram lambs and 132 ewe lambs were retained for breeding. The USSES sires produced 299 offspring with 2 ram lambs and 51 ewe lambs retained. Incorporating external sires resulted in a cumulative percentage of genetic variance of 48.8, 49.1, and 44.2 of external genetics for the reference population, current mature ewe flock, and current mature rams, respectively. Stakeholder needs were addressed by introgression of external sires and participation in NSIP, but future selection practices need to be modified to maintain a minimum of 50% USSES core genetics in the flock.

Pedigree diversity and implications for genetic selection of Katahdin sheep.

The Katahdin hair breed gained popularity in the United States as low input and prolific, with a propensity to exhibit parasite resistance. With the introduction of genomically enhanced estimated breeding values (GEBV) to the Katahdin genetic evaluation, defining the diversity present in the breed is pertinent. Utilizing pedigree records (n = 92,030) from 1984 to 2019 from the National Sheep Improvement Program, our objectives were to (i) estimate the completeness and quality of the pedigree, (ii) calculate diversity statistics for the whole pedigree and relevant reference subpopulations and (iii) assess the impact of current diversity on genomic selection. Reference 1 was Katahdins born from 2017 to 2019 (n = 23,494), while reference 2 was a subset with at least three generations of Katahdin ancestry (n = 9327). The completeness of the whole pedigree, and the pedigrees of reference 1 and reference 2, were above 50% through the fourth, fifth and seventh generation of ancestors, respectively. Effective population size (Ne) averaged 111 animals with a range from 42.2 to 451.0. The average generation interval was 2.9 years for the whole pedigree and reference 1, and 2.8 years for reference 2. The mean individual inbreeding and average relatedness coefficients were 1.62% and 0.91%, 1.74% and 0.90% and 2.94% and 1.46% for the whole pedigree, reference 1, and reference 2, respectively. There were over 300 effective founders in the whole pedigree and reference 1, with 169 in reference 2. Effective number of ancestors were over 150 for the whole pedigree and reference 1, while there were 67 for reference 2. Prediction accuracies increased as the reference population grew from 1k to 7.5k and plateaued at 15k animals. Given the large number of founders and ancestors contributing to the base genetic variation in the breed, the Ne is sufficient to maintain diversity while achieving progress with selection. Stable low rates of inbreeding and relatedness suggest that incorporating genetic conservation in breeding decisions is currently not of high priority. Current Ne suggests that with limited genotyping, high levels of accuracy for genomic prediction can be achieved. However, intense selection on GEBV may cause loss of genetic diversity long term.

Genetic surfing during the range expansion of an endangered large carnivore

In an effort to halt the global decline of large carnivores, reintroductions have become increasingly popular to establish satellite populations and reduce the risk of stochastic events. These artificial range expansions are typically formed by a small number of founders, which can lead to changes in population genetic structure. For instance, serial founder events can lead to neutral and even deleterious alleles reaching higher than expected frequencies along the front end of an expansion, referred to as gene surfing. One of the world’s most extensive range expansion programmes has been for endangered African wild dogs (Lycaon pictus). In this study, we examine the effect of continent-wide translocations on spatial genetic diversity, by determining what effect genetic surfing has on population structure in wild dogs, and measuring how long it will take for population structure to homogenize in the face of ongoing dispersal. We used a set of microsatellite loci to look at surfing alleles in five populations across southern Africa, and simulated the movement of these alleles forward in time under the current demographic scenario. We found that it would take about 150 generations for the expanding population to be 50% introgressed with genes from the free-roaming population. With the current rate of translocations, genetic differentiation in southern Africa will disappear, overturning the effects of genetic drift or surfing alleles. Understanding genetic patterns in expanding populations is of great interest to conservation, and we demonstrate that reintroduction programmes can help restore genetic diversity, and consequently adaptive potential, in recovering wildlife populations.

What Do We Do with the Works of Scandalous Founders in the Catholic Church?

Throughout the 20th century, new religious movements (NRMs) emerged within established religions. Within Catholicism, these NRMs are known as new ecclesial movements and communities. A significant number of founders of these Catholic NRMs have been reported and found guilty of various types of abuses, including sexual abuse, abuse of power, abuse of conscience, and spiritual abuses. This article examines the repercussions of these scandalous behaviors on the foundations and institutions established by the accused founders. Firstly, we investigate how contemporary Catholic communities employ interpretations provided by traditional congregations regarding their founders in the postcouncil era. They utilize these interpretations to legitimize the charismatic founders of their respective movements. Secondly, we assess the feasibility of disentangling the accomplishments of these communities from the shadow cast by their controversial originators. Our findings advocate for the contextualization of works authored by individuals under scrutiny. This approach is presented as a more constructive and effective alternative to wholesale dismissal.

Genetic Variability and Conservation Challenges in Lithuanian Dairy Cattle Populations.

The purpose of the study was to investigate the genetic variability of open Lithuanian Red and Red-and-White (LRWP) and Lithuanian Black-and-White (LBWP) dairy cattle populations and indicate the differences from the old genotypes of Lithuanian Black-and-White (LBW) and Lithuanian Red cattle (LR), which are currently under a conservation program. In order to gain a better understanding of the populations under conservation and to minimize the potential influence of other breeds, a distinct subgroup was formed that comprised animals whose father and mother belonged to the same breed (LR_pure and LBW_pure). The genetic variability was estimated using the number of founders, pedigree completeness, number of males and females in reproduction and age distribution, generation interval (GI), inbreeding coefficient (F) and effective population size (Ne). The highest average pedigree completeness values in the second generations of the old genotype LR and LBW were 100%. Higher ages of females in the populations under conservation were related to a higher GI and their longer life expectancy. In 2021, the reproductive age of bulls used for insemination within these populations ranged from 5.1 to 27.8 years. The proportions of males producing offspring in their older age indicate that the semen was used from the national gene bank of commercial artificial insemination companies. The GI (>5) in LR and LBW females was higher than that in LRWP and LBWP. The analysis of the data over the 15-year period showed that the GI of males in LRWP and LBWP decreased equally by 38%, while in LR_pure population, it increased by 80%. A high (9.24%) average inbreeding coefficient (F) was found in inbred animals of LR_pure population, while in LBW_pure, it was 5.35% in 2021. The coefficient of inbreeding varied within the different cattle populations. In the open LR population, it ranged from 1.48% to 2.7%, while in the LRWP population, it fell between 2.12% and 3.72%. The lowest effective population size (Ne) concerning the rate of inbreeding was observed in LBW_pure (23) and LR_pure (59), with the highest Ne identified in the LBWP population (462). When considering Ne based on the number of parents, LR_pure displayed the lowest Ne (42), while the highest Ne was found in LBWP (4449). An analysis of local cattle populations reveals that LR faces the most critical situation. This particular population has been steadily declining for a number of years, necessitating additional measures and efforts to safeguard the LR's ancestral genetic makeup. The results of the LBWP analysis also highlight a concerning trend. Even in very large populations with open breeding programs, the effective population size per generation can experience a significant decrease.

Examining the influence of specific IC elements on alliance formation of new ventures

PurposeIntellectual capital (IC) is essential to the success of new technology-based firms. However, young firms only possess some of the resources and capabilities needed to develop, produce and market their innovative products and services. Hence, many form alliances to access complementary resources. This paper investigates the signaling effect of technology-based start-ups’ stock of IC on alliance formation.Design/methodology/approachThis study analyzes primary data concerning specific classes of IC and the alliances formed. Data were collected from founders of 233 technology-based new ventures in the USA. Hypotheses were tested via hierarchical linear regression.FindingsThis study demonstrates that firms' IC, in the form of founders with doctorates and patents, is positively related to the classes of alliances formed. These stocks of IC send signals about credibility to the market for alliance partners, enabling the firms to form alliances and gain access to complementary resources. The number of founders with doctorates was positively related to R&D alliances and alliance partners in a similar place in the value chain as the focal firm. In contrast, the number of patents was positively related to total alliances, production-oriented alliances and alliances considered upstream from the focal firm.Originality/valueThis paper collects retrospective data from founders of technology-based new ventures. The research contributes to the literature with its results that founder human capital and patent portfolios are essential for technology-based firms' innovation and growth. However, little research has investigated how firms' possession of IC facilitates alliance formation. This paper investigates this connection explicitly.

Pedigree-based analysis of genetic variability in the Chinese Crested dog population in Poland

The aim of the study was to analyse the level of genetic diversity within the small-sized population of Chinese Crested dogs bred in Poland, considering the common occurrence of hereditary diseases, probably related to the high level of inbreeding. The pedigree data provided by Polish Kennel Club were used to estimate different genealogical parameters in the ancestral (n=1,860) and active population (n=1,313). The mean equivalent number of complete generations known per animal reached 5.97 and 6.75 generations in the ancestral and active populations, respectively. The mean inbreeding coefficient values were 0.083 and 0.049 in the ancestral and in the active population, respectively. The effective number of founders (fe) and ancestors (fa) and the ratio fa/fe were 38, 20, 0.54 and 79, 34, 0.43 in the ancestral and active population, respectively. It should be concluded that the genetic variability of the Chinese Crested dogs in Poland is currently at a satisfactory level. However, high proportion of related male-female pairs may cause future mating problems. The population should be monitored for inbreeding and genetic variation. The breeders should choose reproducers in such a way as not to create large groups of paternal half-siblings in the offspring.