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Avian Genetics & DNA Testing — Glossary¶

A — General Terms¶

Term	Abbreviation	Definition
Allele	—	One of two or more alternative forms of a gene, arising by mutation and found at the same place (locus) on a chromosome
Amplicon	—	DNA fragment produced by PCR amplification of a specific target sequence
Analytical Sensitivity	LOD	Limit of detection — the lowest concentration of target that can be reliably detected (≥ 95% of the time)
Analytical Specificity	—	Ability of an assay to detect only the intended target without cross-reacting with related or non-target organisms
Annealing	—	Step in the PCR cycle where primers bind (hybridize) to complementary sequences on the single-stranded DNA template
Avian Polyomavirus	APV	DNA virus (family Polyomaviridae) causing acute disease, particularly in young psittacines; characterized by hemorrhage, ascites, and sudden death

B — Diagnostic & Pathogen Terms¶

Term	Abbreviation	Definition
Beak and Feather Disease Virus	BFDV	Circovirus (family Circoviridae) that causes PBFD — progressive feather dystrophy, beak deformities, and immunosuppression in psittacines
Bland-Altman Analysis	—	Statistical method for comparing two measurement techniques by plotting the difference between paired measurements against their mean
Capillary Electrophoresis	CE	High-resolution DNA fragment separation method using a thin capillary filled with polymer matrix and fluorescence detection; used for microsatellite genotyping and STR analysis

C — CHD Gene & Sex Determination¶

Term	Abbreviation	Definition
CHD Gene	CHD	Chromodomain Helicase DNA-binding gene — a conserved gene family used as the standard target for avian DNA sexing because of its presence on both sex chromosomes with different intron sizes
CHD-W	—	Female-specific copy of the CHD gene located on the W chromosome (only present in ZW females)
CHD-Z	—	Copy of the CHD gene located on the Z chromosome (present in both ZZ males and ZW females)
Circovirus	—	Family Circoviridae — small (≈ 2 kb) circular single-stranded DNA viruses including BFDV, PiCV, and PCV2
Clinical Sensitivity	DSe	Proportion of true positive samples correctly identified by the test — true positives / (true positives + false negatives)
Clinical Specificity	DSp	Proportion of true negative samples correctly identified by the test — true negatives / (true negatives + false positives)
Cloacal Swab	—	Sample collection method using a sterile swab inserted approximately 1 cm into the cloaca and rotated gently to collect epithelial cells and microorganisms
CMA	—	China Metrology Accreditation — Chinese equivalent of ISO/IEC 17025 for laboratory competence
CNAS	—	China National Accreditation Service — the national accreditation body for conformity assessment in China
Ct Value	Ct	Cycle threshold — in qPCR, the PCR cycle number at which the fluorescence signal of the target crosses the background threshold; inversely proportional to the initial target quantity
Denaturation	—	Step in the PCR cycle where double-stranded DNA is heated (typically 94–98°C) to separate it into single strands
Diagnostic Sensitivity	DSe	Same as clinical sensitivity — see above
Diploid	—	Having two complete sets of chromosomes (2n) — all somatic cells in birds are diploid

D — DNA & Genetic Profiling¶

Term	Abbreviation	Definition
Discrimination Power	DP	In DNA fingerprinting: the probability that two randomly selected individuals have different genotypes; DP > 0.9999 is considered acceptable for forensic identification
DNA Fingerprinting	—	Genetic profiling technique using microsatellite (STR) markers to generate a unique DNA profile for individual identification, parentage verification, and population studies
DNA Sexing	—	Molecular determination of biological sex by detecting the presence or absence of sex chromosome-specific DNA markers (CHD-W for females, CHD-Z for both sexes)
DRD4	—	Dopamine receptor D4 gene — encodes a G-protein-coupled receptor involved in dopamine signaling; polymorphisms associated with exploratory behaviour, homing motivation, and stress tolerance in racing pigeons
Dynamic Range	—	In quantitative assays: the range of target concentrations over which the assay produces a proportional signal, bounded by LOD and the highest quantifiable concentration

E — Extraction & Sample Terminology¶

Term	Abbreviation	Definition
EDTA	—	Ethylenediaminetetraacetic acid — a chelating agent used as an anticoagulant in blood collection tubes (purple-top tubes); binds calcium, preventing blood clotting
Electropherogram	—	Graphical output of capillary electrophoresis showing a series of peaks, each representing detected DNA fragments (by size and fluorescence intensity)
Extension	—	Step in the PCR cycle where Taq polymerase adds nucleotides to the primer, extending the new DNA strand (typically at 72°C)
FTA Card	—	Specialized filter paper impregnated with chemicals that lyse cells, denature proteins, and stabilize nucleic acids at room temperature for extended periods

G — Genetics & Genomics Terms¶

Term	Abbreviation	Definition
Genotype	—	The genetic constitution of an individual at a specific locus or set of loci — usually represented as a pair of alleles (e.g., AA, Aa, aa)
Hardy-Weinberg Equilibrium	HWE	Principle stating that allele and genotype frequencies in a population remain constant from generation to generation in the absence of evolutionary influences; deviation may indicate selection, inbreeding, or population structure
Heterogametic	—	Having two different sex chromosomes — in birds, females are heterogametic (ZW)
Heterozygosity	—	The proportion of individuals in a population that carry two different alleles at a given locus; a measure of genetic diversity
Homogametic	—	Having two identical sex chromosomes — in birds, males are homogametic (ZZ)

I — ISO & Quality Standards¶

Term	Abbreviation	Definition
ISO 13485	—	International standard for quality management systems specific to medical devices, including in vitro diagnostic (IVD) products
ISO 9001	—	International standard for general quality management systems, applicable to any organization
LDHA	—	Lactate dehydrogenase A gene — encodes the A subunit of lactate dehydrogenase; catalyzes the conversion of pyruvate to lactate in anaerobic metabolism; associated with sprint performance and recovery in racing pigeons
Levey-Jennings Chart	—	Quality control chart used to monitor assay performance over time by plotting measured values (e.g., Ct of a control sample) against established mean and standard deviation limits

M — Microsatellite & Molecular Markers¶

Term	Abbreviation	Definition
Microsatellite	STR	Short Tandem Repeat — a DNA sequence motif of 2–6 base pairs repeated in tandem; highly polymorphic and widely used for DNA fingerprinting, parentage analysis, and population genetics
Multiplex PCR	—	Simultaneous amplification of two or more target sequences in a single PCR reaction using multiple primer pairs; used extensively in SENO's 11-pathogen disease panel
NMPA	—	National Medical Products Administration (China) — the regulatory authority overseeing medical devices, IVD reagents, and pharmaceutical products in China
Nucleic Acid	—	DNA (deoxyribonucleic acid) or RNA (ribonucleic acid) — the genetic material of all living organisms

P — Pathogen & Disease Terms¶

Term	Abbreviation	Definition
Pathogen	—	Microorganism capable of causing disease — includes viruses, bacteria, and fungi
PCR	Polymerase Chain Reaction	Method to exponentially amplify a specific DNA sequence through repeated cycles of denaturation, annealing, and extension using a thermostable DNA polymerase
PiADV	—	Pigeon Adenovirus — DNA virus causing hepatic necrosis and enteritis ("young bird sickness") in pigeons
PiCV	—	Pigeon Circovirus — small circular ssDNA virus causing immunosuppression in young pigeons, similar to BFDV in psittacines
PiHV	—	Pigeon Herpes Virus — DNA virus causing respiratory distress and hepatic necrosis in pigeons
Polymorphism	—	Naturally occurring genetic variation in a population — may be a single nucleotide change (SNP), repeat length variation (VNTR), or structural variant
PPMV-1	—	Pigeon Paramyxovirus Type 1 — RNA virus closely related to Newcastle Disease Virus, causing neurological signs, green diarrhea, and mortality in pigeons
Primer	—	Short (18–25 nucleotide) single-stranded DNA sequence designed to bind specifically to a complementary region on the target DNA; provides the 3' hydroxyl group for Taq polymerase to begin extension
Probability of Identity	PI	In DNA fingerprinting: the probability that two individuals share the same genotype by chance; PI > 10⁶ is considered acceptable for individual identification
Proficiency Testing	PT	External quality assessment where a laboratory's test results are compared against a reference laboratory or peer group to ensure accuracy
Psittacine	—	Bird belonging to the order Psittaciformes — the parrot family, including macaws, cockatoos, African greys, Amazons, parakeets, and lovebirds

Q — Quantitative PCR & Assay Terms¶

Term	Abbreviation	Definition
qPCR	Quantitative PCR	Real-time PCR — amplifies and simultaneously quantifies target DNA by measuring fluorescence emitted during each cycle; uses either double-stranded DNA-binding dyes (SYBR Green) or target-specific probes (TaqMan)
ROC Curve	ROC	Receiver Operating Characteristic curve — plots true positive rate (sensitivity) against false positive rate (1 − specificity) across all possible threshold values; AUC ≥ 0.95 indicates excellent discrimination
RT-PCR	Reverse Transcription PCR	PCR preceded by conversion of RNA to complementary DNA (cDNA) using reverse transcriptase; required for detection of RNA viruses such as PPMV-1, NDV, and AIV

S — Sample & Species Terms¶

Term	Abbreviation	Definition
Sensitivity	—	Refers to analytical sensitivity (LOD) or clinical sensitivity (DSe) depending on context — see specific entries above
Specificity	—	Refers to analytical specificity or clinical specificity (DSp) depending on context — see specific entries above
STR	Short Tandem Repeat	See microsatellite above
Taq Polymerase	—	Heat-stable DNA polymerase originally isolated from Thermus aquaticus; used in PCR for its ability to withstand the high temperatures required for DNA denaturation

Z — Sex Chromosome System¶

Term	Abbreviation	Definition
ZW System	—	Avian sex chromosome system: males are homogametic (ZZ), females are heterogametic (ZW). This is opposite to the mammalian XY system where males (XY) are heterogametic

Cross-References¶

CHD PCR Protocol — Sex determination methodology
Accuracy Validation — Validation terminology in practice
Performance Gene Testing — Genetics of racing pigeon traits
Pigeon Disease Panel — Pathogen abbreviations in context

This glossary is maintained by SENO's R&D team and updated as new terms are introduced. For corrections or additions, contact [email protected].