Linkage and Its Estimation and Chromosome Mapping

UPDATED ON:- 01-01-2024

सहलग्नता व इसका मापन और गुणसूत्रीय मापन (Linkage and Its Estimation and Chromosome Mapping):-

सहलग्नता (Linkage):- एक गुणसूत्र पर पास – पास उपस्थित 2 युग्मविकल्पी जब साथ – साथ वंशागत होते हैं तो इसे सहलग्नता कहते हैं।

(When two alleles present together on a chromosome are inherited together, it is called linkage.)

नोट:- जीन विनिमय अधिकतम 50% ही हो सकता है।

(Note:- Crossing over can be up to 50% only.)

सहलग्नता मापन या गुणसूत्रीय मापन (Linkage Estimation or Chromosome Mapping):- गुणसूत्र पर उपस्थित जीनों के क्रम व उनके मध्य जीन विनिमय की आवृति को निर्धारित करने की प्रक्रिया को सहलग्नता मापन कहते हैं।

(The process of determining the sequence of genes present on a chromosome and the frequency of crossing over between them is called linkage mapping.)

विधि (Procedure):-

Ø  सबसे पहले Parent types को पहचानते हैं जो Highest Number में दिये होते हैं।

(First of all, identify the parent types which are given in the highest number.)

Ø  अब Recombinant types को पहचानते हैं।

(Now identify the Recombinant types.)

Ø  अब सभी individuals की संख्याओं को जोड़कर Total Individuals ज्ञात कर लेते हैं।

(Now sum up the numbers of all the individuals and find out the total Individuals.)

Ø  अब आवृति ज्ञात करते हैं।

(Now find out the frequency.)

Ø  दो जीनों के बीच की दूरी निम्न सूत्र से निकालते हैं:-

(Find the distance between two genes by the following formula:-)

Ø  मध्य जीन की पहचान (Identification of Middle Gene):- DCO की Parent type से तुलना करते हैं। जो जीन Parent type की तुलना में DCO सन्तति में विनिमय प्रदर्शित करता है, वही मध्य जीन होता है।

(Compare DCO with Parent type. The gene which shows exchange in the DCO progeny as compared to the parent type is the middle gene.)

Ø  अब गुणसूत्र माप बना देते हैं।

(Now draw the chromosome map.)